Summary: It's well made, compact and fast, with a great screen and impressive camera, at least in daylight. The Android 4.0 update is also welcome, as it makes the phone feel significantly faster, but at the expense of some battery life. The phone also feels like a classy bit of kit, especially considering it's currently price.
Summary: Nice phone, good touchscreen, great battery life. My only complaint is that the gps sensor seems not as good as other phones I've owned in the past. it takes a very long time to locate my position, and with apps like jogtracker it may never find my position during the duration of the run. I assume this is a problem with the phone and not the service, I use T mobile.
Summary: My wife wanted a small enough but capable smartphone and that's what she got with the Xperia U. She doesn't like big fancy phones, mostly because she's got small hands, so we were looking for an ideally sized phone and found it on the Xperia U. For her needs it more than fits the bill. It feels snappy enough and takes excellent pictures for the size. My wife is perfectly happy with it.
Summary: The fact that the Facebook app comes pre-installed with ALL permissions and is running at all times in the background is extremely annoying. But if you upgrade the OS from Gingerbread to Ice Cream Sandwich, you can suspend those annoying apps. Light bar is cute but sometimes annoying when you light up a dark theater looking at a text -- of course you can set your phone to vibrate so as not to disturb others, but there seems to be no way to shut off the light bar.
Summary: I purchased this phone as a back up to my iPhone 4S and recieved many compliments on the cool factor. My AT&T SIM card worked perfectly in this phone. I will say I do not game, play music or use social networking software on my cell phones. I simply text, surf and talk.