First things first: To even order a One, you'll need an invite from the company or those who already have one. OnePlus says it is doing this because it is a new company and is looking to manage its early inventory. The company is currently selling the One only through its website, but says it is open to partnering with others.

You can get a 16GB version of the One for $299 and a 64GB model for $349, and both versions are available in silk white or sandstone black. To put that in perspective, the Galaxy S5 without a contract costs $650 from AT&T and $599 on Verizon.

It doesn't just look good, it feels good. The rectangular phone's slightly curved rear has a gritty, sandpaper-like texture that makes for an easy grip. Up front, the One's glossy 5.5-inch Corning Gorilla Glass 3 panel is framed by silver-gray edges and a thin bezel that you'll only notice when the screen is turned on.

Above the display sits a speaker and a 5-megapixel camera beside an LED indicator light. Soft keys for Menu, Home and Back reside beneath the display. By default, the keys' backlight turns off after 3 to 5 seconds of inactivity, which can make them somewhat difficult to find. Thankfully, you can set the backlight to always be on, but even then the light is dim.

We would have preferred that OnePlus swapped the Menu button for a Recent Apps key. You'll need to long-press the Menu key to switch between open apps by default, but you can set the home key to do this when long-pressed.

On the One's left edge is a volume rocker and a discrete microSIM card slot, while the right has a power button. A 3.5mm audio jack sits atop the device while a microUSB port anchors the bottom, flanked by two stereo speakers.

The One doesn't offer onboard memory expansion options such as a microSD card slot, which can be somewhat limiting for the 16GB base version, especially for those who want to shoot 4K video.

At 6.0 x 2.9 x 0.35 inches, the OnePlus One is larger than such leading flagship phones as Samsung's Galaxy S5 (5.3 x 2.9 x 0.25 inches), HTC's One M8 (5.8 x 2.8 x 0.37 inches) and LG's G3 (5.8 x 2.9 x 0.36 inches). The OnePlus has a 5.5-inch display, though, which is larger than the S5's 5.1-inch and the HTC One M8's 5-inch faces. The G3 has the same size screen as the OnePlus.

The 5.7-ounce OnePlus One feels sturdy, but is heavier than the Galaxy S5 (5.1 ounces), the HTC One M8 (5.6 ounces) and the LG G3 (5.3 ounces).

We loved the One's bright, beautiful and responsive 5.5-inch, 1920 x 1080 Gorilla Glass display. A 1080p trailer for "Guardians of the Galaxy" looked tantalizingly clear and colorful. Gamora's green skin popped against her raven black locks. Details, such as individual strands of hair on Rocket Raccoon's face, were tack sharp. The OnePlus One offers wide viewing angles, too, with images retaining their color and quality as we tilted the phone's screen from side to side.

Competing smartphones, such as the Galaxy S5 (5.1-inches; 1920 x 1080) and the HTC One M8 (5-inches; 1920 x 1080) have equally sharp screens on smaller faces. The LG G3, however, boasts a super-sharp 2560 x 1440 resolution on a 5.5-inch panel.

Measuring 432 nits on our light meter, the One's display is the brightest in its class. The average smartphone comes in at a dimmer 352 nits, while the Galaxy S5 (373 nits), One M8 (402 nits) and G3 (272 nits) also lagged behind the One.

Unfortunately, the One fell behind the competition on our sRGB Gamut test, displaying 92.7 percent of the color spectrum. That's less than the average smartphone (118 percent), the One M8's 116.1 percent, the Galaxy S5's 158.4 percent and the LG G3's 98.2 percent. We like to see closer to 100 percent, if not beyond.

The One's color accuracy could also be better. The screen registered a Delta-E score of 8.6 (closer to 0 is best), which is worse than the average smartphone (5.29). The One M8 (5.9), LG G3 (1.5) and the Galaxy S5 (0.1) all deliver more accurate colors (numbers between 1 and 0 are better).

The One's dual bottom-facing JBL speakers won't blow you away, but they're good enough to fill a medium-size room with decent sound. While Christina Aguilera sounded slightly canned in "Feel This Moment," guitars, pianos and vocals were crisp in "If I Had $1,000,000" by the Barenaked Ladies.

Notching 86 dB on Laptop Mag's audio test, which involves playing a tone and measuring it from 13 inches, the One is louder than the average smartphone (80 dB), the S5 (70 dB) and the 85-dB G3. It fared the same as the One M8 (86 dB), but that phone has more robust sound.

An onboard Audio FX app offers an equalizer with 13 preset profiles, such as Dance, Pop, Classical, Electronic and Custom, along with bass boost and surround sound toggles to let you adjust the level of each setting. You can also choose a reverb mode such as Small Room, Medium Room, Large Room, Small Hall or Medium Hall. These settings can be applied to inserted headphones, the device's own speakers or paired outputs via Bluetooth or Wi-Fi.

During our testing, we saw no difference at all across all the profiles and settings in headphone mode and heard a difference only when we switched between Small Speakers and Electronic profiles when using the device's own speakers. OnePlus said CyanogenMod is aware of the issue and that Audio FX isn't working perfectly with every app, but that the OS team is working on fixing the issue.

What's the big deal about CyanogenMod? It's basically Android but with more personalization and security options built in so you don't have to install separate apps to get the same features. The operating system is also free of bloatware.

Running CyanogenMod 11S, which is built upon Android 4.4 KitKat, the OnePlus One's system looks almost identical to the stock OS but with some noticeable differences. You'll see this first in the lock screen. Instead of a clock widget in the center of the display, you get a page split in half -- an empty pink top and baby blue bottom. A digital clock is on the top of the blue section, which you pull down to unlock the device. This lock screen can be changed depending on the theme you choose.

The home screen looks identical to Android KitKat's, except you get different icons for apps such as Dialer, Messaging, Camera, Downloads, File Manager and Email. These are CyanogenMod's own versions of what Android normally offers, and they're often more feature-rich than stock versions (more below).

You'll also find the notification drawer and quick settings panel familiar. A row at the top lets you quickly toggle connectivity, volume and brightness modes, and you can arrange these however you like.

Having CyanogenMod also means you have access to the latest version of Android, since the team behind the system provides updates more frequently than carriers, who can take months to update devices on their network.

OnePlus is also working on implementing a Siri-like voice wake/search feature that will let you activate the One by saying "OK, OnePlus."

CyanogenMod packs a nifty feature that makes it easier to trigger commonly used tasks. When the setting is activated, you can use unique CyanogenMod gestures on your lock screen to quickly trigger functions.

For instance, drawing a V on the One's face turns on the LED flashlight feature, while a circle opens the camera app. You can also control your music playback by drawing vertical lines with two fingers to play or pause, and left or right arrows for previous or next tracks, respectively. While these gestures can be individually enabled or disabled, you can't create any custom gestures for now.

We loved starting the camera app quickly and easily just by drawing a circle on the screen, even when the device is asleep. The V to start the torchlight did not work as well, lagging from time to time. When it worked, though, it was a handy feature to use when stumbling about in a dark apartment.

You can also set the device's soft keys to perform different tasks when the One is locked, such as toggling sound on/off, going to sleep, turning on the torch or skipping songs.

Not only do you get to define what your OS looks like on the OnePlus One by downloading and installing themes, you can also configure such layouts as the specific tiles in your quick settings panel. The power menu that launches when you hold the power button down also offers more options than stock Android. You can reboot, switch profiles and change sound modes, in addition to the usual toggling of airplane mode and powering off.

CyanogenMod also gives you finer control over your phone. For instance, instead of just being able to adjust the general volume for your keypad and ringer, the One lets you specifically toggle how loud your alarms, ringtones and music and games are.

You can also define what the buttons on the One do when tapped or long-pressed. By default, long-pressing the home button pulls up the Google Now search assistant, but you can change this to open the recent apps switcher, voice search, in-app search, camera app or the layout menu.

The One also comes with a whole bunch more notification and ringtone options out of the box than Android devices. An expanded desktop mode hides your navigation and status bar to give you more of your screen, and you can swipe from the top or bottom of the screen to pull up the bars for a few seconds.

Worried about the NSA (or anyone else) snooping on you? If you text your friends who also run CyanogenMod on their phones, your messages will be encrypted as you send them, so even if they are intercepted the hacker will just see gibberish. Since there aren't too many people using CyanogenMod phones, we aren't sure how useful this feature is yet.

A Privacy Guard tool lets you better manage your app permissions by showing you all the apps in your phone and letting you choose whether to grant each title access. Tapping advanced options in the Privacy Guard menu gives you finer control over the exact type of data -- location, personal, messaging, media, device and bootup -- each app is allowed.

We opened the permissions for Songza and were able to allow or deny the app access to such settings as volume, Media Buttons, Notifications and Keep Awake. You won't get such a la carte settings on mainstream Android devices.

In this directory, you also see how many times each app has accessed the relevant data. For instance, under the Personal category, we saw that the Google+ app had read our contacts 137 times, and modified entries 75 times.

The One uses the SELinux (Security-Enhanced Linux) security module, which was first developed by the NSA, and fine-tunes which processes can do what on Linux-based devices.

CyanogenMod packs in a few nifty apps that make your phone more useful out of the box. A Torch app lets you turn on the camera's dual LED flash to use as a flashlight, and a Screencast app lets you record what's going on your screen. Themes Showcase makes it easy to find and install new theme packs.

In place of the regular Android versions of Camera, Downloads, Gallery, Messaging and People apps are CyanogenMod's tweaked versions. These apps are often more feature-rich than Google's. For instance, the File Manager lets you lock your device storage so no one can write to it, and offers different views and arrangements of your documents.

You also get some standard Android fare such as Google+, Chrome, Gmail, Hangouts, YouTube, Play Music, Play Games, Play Store, Maps, Drive and Calendar.

Equipped with a 2.5-GHz quad-core Snapdragon 801 CPU with 3GB of RAM and 64GB of storage, the One is quite the performance powerhouse. We played three rounds of "Riptide GP 2" with no lag despite apps such as Camera, Phone, People, Settings and Play Store open in the background.

Taxing games such as the first-person shooter "N.O.V.A. 3" ran smoothly, and opened in 15 seconds, a second faster than the average smartphone. The Galaxy S5 was slower (19 seconds) but the LG G3 took the same time. The HTC One M8 was faster, taking just 12 seconds.

All three competing smartphones use the same quad-core Snapdragon 801 CPU, with the LG packing 3GB of RAM and the Samsung and HTC offering 2GB.

The One did well on our video-editing test, taking 5 minutes and 58 seconds to transcode a 204MB 1080p video clip to 480p. The average smartphone (7:59) and the LG G3 (6:37) were slower, but the One M8 (5:00) and Galaxy S5 (4:42) were faster.

On general performance benchmark Geekbench 3, the OnePlus's score of 2,504 puts it ahead of the average smartphone (1,806), the G3 (2,217) and the One M8 (2,324). However, the Galaxy S5 scored a higher 2,897.

You'll find the One quite capable of delivering good graphics performance. Notching 18,399 on 3DMark Ice Storm Unlimited, the One beat the average smartphone (12,036) and the LG G4 (15,395), although the latter's lower score may be due to its higher display resolution. The One lagged the Galaxy S4 (18,547) and the HTC One M8 (20,640).

You'll love the shots you take with the One's 13-megapixel Sony camera. It packs six lenses to avoid distortion and color aberration. Our pictures of the Flatiron District looked vibrant and sharp, with individual windows in buildings clearly delineated even at 100 percent zoom on a desktop monitor. Colors--such as red buildings, yellow cabs and blue awnings--looked accurate and vivid.

Running over AT&T's 4G LTE network (we inserted our own SIM), the OnePlus One runs circles around other smartphones when it comes to battery life. On the Laptop Mag Battery Test, which consists of continuous Web surfing at 150 nits of screen brightness, this device's 3,100 mAh battery lasted a whopping 13 hours and 16 minutes. The Galaxy S4 (9:42), the HTC (8:42) and the LG G4 (7:56) all delivered much shorter runtimes.