The Samsung Galaxy S II Skyrocket ($149.99) is a big slab of Android, but with a twist: It's one of the first two smartphones to support AT&T's brand new 4G LTE network, the other being the HTC Vivid ($99.99, 4 stars). We're giving the Editors' Choice nod to the Skyrocket, thanks to its faster performance, lightweight design, and vibrant (if not as high resolution) screen, but the Vivid is also a very powerful smartphone—you can't go wrong with either one.

Design, Screen, and Call Quality
The Skyrocket looks a lot like the Galaxy S II ($99.99, 4.5 stars). It features a matte, slightly textured back panel, black glossy plastic sides. It measures 5.15 by 2.75 by 0.37 inches (HWD) and weighs 4.65 ounces. At least, that's what Samsung and AT&T both claim. But if you lay the Skyrocket flat on a table and place a ruler next to it like I did, you'll find it's actually about 0.42 inches deep. It sticks up noticeably higher than an iPhone 4 I had nearby (which rings in exactly at its quoted 0.37 inch figure). The Skyrocket is still thinner than other LTE devices we've tested, though, and it's certainly lighter in weight.

The massive 4.5-inch, 480-by-800-pixel, Super AMOLED Plus display is as vibrant and colorful as on other Samsung phones; it's also two tenths of an inch larger than the Galaxy S II's display. But at this screen size, I'd like to see more pixel density. On the plus side, you can read it outdoors, which was a problem with earlier AMOLED panels, and the gorgeous color and deep blacks really stand out. On a screen this size, you get big keys, so typing on the on-screen keyboard isn't a problem in either portrait or landscape mode.

The Skyrocket is a quad-band EDGE (850/900/1800/1900 MHz), tri-band HSPA+ (850/1900/2100 MHz), and dual-band LTE (700/1700 MHz) device. It also has 802.11b/g/n Wi-Fi; it connected to my own WPA2-encrypted network without issue.

There's no getting around it: LTE is fast. In a series of tests in and around Boston, MA, I saw data speeds ranging from 16Mbps to 25Mbps down, and 12Mbps up. Be aware that AT&T is still building out its LTE network; currently, it's only available in nine cities in the U.S. When not in an LTE area, the Skyrocket is rated as an HSPA+ 21 device; the Vivid is just HSPA+ 14.4. However, I saw roughly the same real-world HSPA+ speeds with both the Vivid and the Skyrocket, averaging up to 8Mbps down.

The Skyrocket is also a good voice phone. Callers sounded warm and clear through the earpiece, with no background hiss. The only flaw I heard was a faint wash of static around some syllables, but I had to strain to hear it in a very quiet room. Transmissions through the microphone were clear. Calls also sounded fine through a Jawbone Era Bluetooth headset ($129, 4 stars). Voice dialing doesn't work over Bluetooth, which is a bizarre omission on a top-of-the-line smartphone. The speakerphone went quite loud, but distorted considerably at several of the higher volume settings; you won't want to use it for long conference calls. Battery life was good at 6 hours and 47 minutes of talk time.

Apps, Multimedia, and Conclusions
Samsung Android phones often have key characteristics, all of which are present here: the four capacitive touch buttons beneath the screen; the pull-down bar at the top that lets you configure the radios; and a lighter overall UI overlay than what you find on HTC and Motorola phones. You get seven customizable home screen panels, most of which Samsung pre-populates with various widgets.

The 1.5GHz Qualcomm dual-core CPU and Android 2.3.5 (Gingerbread) OS make this a totally up-to-date Android device (for now, at least); it should have no problem running most of the quarter million third-party apps in the Android Market. That said, our benchmark results virtually matched those of the Galaxy S II, which contains a 1.2GHz Samsung Exynos processor. The Skyrocket is still very fast, but I had hoped for a noticeable bump in the benchmark results.

Multimedia fans will find much to like here. There's 16GB of internal storage, plus a microSD card slot underneath the battery cover; my 32GB SanDisk card worked fine. You don't have to pull the battery to swap cards like you do with the HTC Vivid, which is a big plus. Music tracks sounded full and vibrant through Samsung Modus HM6450 Bluetooth headphones ($99, 4 stars). As usual, Samsung provides a good-sounding set of wired stereo earbuds in the box, which is something we wish other phone vendors would do. The music player displayed huge album art thumbnails when available, and cycled through a series of attractive music-themed graphics otherwise, which was a nice touch. Standalone videos played smoothly and vibrantly in full screen mode, even DivX and Xvid videos, at resolutions up to 1080p. Thanks to the screen size and deep blacks of the super AMOLED screen, this is a heck of a pocket video player.

The 8-megapixel auto-focus camera has a single LED flash. Test photos looked very sharp, with good detail both indoors and outside. There were a few minor flaws: Bright sunlight overwhelmed the sensor in a few shots. One indoor shot was slightly blurry, and the flash didn't help much in a dimmer room. But for the most part, this is one good camera. Recorded 1080p videos played smoothly at 28 frames per second, but looked a little dull and shaky; there's no image stabilization, which would have helped. Stepping down to 720p (1280-by-720) bumped the frame rate to an even 30 frames per second, zoomed back out properly, and looked more natural.

The Skyrocket is a powerful phone, and its LTE capability means you're buying into a future of super-fast data speeds. The HTC Vivid is $50 cheaper, has a sharper screen that's almost as vibrant, and HTC's Sense UI layer adds useful enhancements. But the Vivid is heavier, and not quite as fast from a CPU standpoint. The Motorola Atrix 2 ($99.99, 4 stars) lets you hook into Motorola's interesting array of Webtop-related accessories, and it also has a higher-resolution screen, but it's not an LTE phone. Finally, we haven't tested AT&T's version of the Apple iPhone 4S ($199.99, 4.5 stars), though we expect it to be a solid choice. It features a top-notch camera, vast app catalog, Siri voice assistant, and smooth OS. It lacks any kind of 4G, though, and its Retina screen, though sharper, is a full inch smaller than the Skyrocket's.

Benchmarks
Continuous talk time: 6 hours 47 minutes

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