The Epic 4G sports an outdoor-viewable Super AMOLED screen, a 1-GHz Hummingbird processor and a full QWERTY keyboard. I spent a bit of time with a prototype phone last week, and came away impressed, but concerned.

Let's start with the impressive parts. Super AMOLED screens are super-bright, and the colors look oversaturated. Color experts like Raymond Soneira may frown upon that, but it makes for a very lively look. The Epic's five-row QWERTY keyboard is unusually spacious, and it's both comfortable and clicky. I'm picky about keyboards, and I found the Epic's to be excellent.

The Epic's build is an otherwise typical mid-to-high-end smartphone, with relatively classy plastic components, with a solid slider and a soft-touch back.

The Epic's 1-Ghz Hummingbird processor has a GPU that supposedly renders 89 million triangles per second, which is four times what Qualcomm's competing Snapdragon processors crank out. The big question there is what aspects of the Android experience are controlled by the GPU. Will excellent graphics performance accelerate Flash? Video streaming? HD video playback? I'm raring to find out.

The Epic also has a 5-megapixel camera on the back and all the usual goodies: Wi-Fi, Bluetooth, GPS, Wi-Fi hotspot capability and Sprint's new WiMAX 4G network, which drains battery life but delivers high data speeds.

The Epic 4G will come with at least one important exclusive app, a Samsung content-delivery service which will let device owners download major-studio movies and TV shows.

But here's the worry. The Epic runs the world's most pointless Android skin, Samsung's TouchWiz. Unlike HTC's Sense and Motorola's Blur, TouchWiz doesn't seem to be devoted to delivering concrete additional functionality to your phone. Mostly, it just seems to be devoted to making things look different. I'm worried that TouchWiz will delay Android upgrades without really adding much to the experience.

Sprint did confirm that the Epic will get an Android 2.2 upgrade, along with Adobe Flash, though they didn't promise a date.

Sprint's "4G" designation comes from the fact that it can tie into Sprint's 4G or WiMAX service, like its first 4G smartphone, the EVO 4G.

Now Sprint just needs to get 4G service into more cities. The company says 4G is coming to Boston, Cincinnati, Cleveland, Denver, Los Angeles, Miami, Minneapolis, New York, Pittsburgh, Salt Lake City, San Francisco, St. Louis and Washington, D.C. by the end of the year.

Sprint didn't announce a price for the Epic, but the company said it would be available later this summer.