Well, let’s hope they’re NASA engineers, because this feature is head-bangingly unstable. After two days of fiddling, downloading and uninstalling apps, manually force-quitting programs and waiting for servers to be upgraded, I finally got video calling to work — sort of. Sometimes there was only audio and a black screen, sometimes only a freeze-frame; at best, the video was blocky and the audio delay absurd.

To make video calling work, you have to install an app yourself: either Fring or Qik. But we never did get Fring to work, and Qik requires people you call to press a Talk button when they want to speak. The whole thing is confusing and, to use the technical term, iffy.

But come on — this is the first 4G phone in America! That’s got to be better than 3G, right?

Hard to say, since I couldn’t find any 4G reception, even in weeks of traveling. My problem, evidently, was that I was visiting major cities like New York, Boston and San Francisco. So far, Sprint has installed 4G coverage in only 32 areas — and they’re bustling metropolises like Boise, Idaho; Wichita Falls, Tex.; High Point, N.C.; and Milledgeville, Ga.

Image The Sprint Evo 4G seems spectacular, but has some significant drawbacks. Credit... Paul Sakuma/Associated Press

Fortunately, my Times tech colleague, Roy Furchgott, has three things going for him: he also had an Evo to test, he’s a fellow tech reporter and he lives in Baltimore, one of the 4G cities. So I asked him to put the Evo through its paces for me.

His tests indicate that 4G Internet downloads are about four times as fast as 3G (averaging 2,693 kilobits a second, versus 676 over 3G). He noted that Internet videos don’t stutter, and of course e-mail attachments fly in.

He also noted, however, that the 4G signal was “spottier than a kennel of Dalmatians.” At his house, he sees four to five signal bars, but two blocks away there is no reception at all. Furthermore, it takes 20 seconds for the phone to recognize that a 4G signal is available, then six minutes to connect for the first time.