Had the phone for 4 days now and very impressed with nearly everything. A good improvement over my Arc and a HUGE improvement over the phone it replaced - an X10.
+ Phone sound and volume
+ Screen brightness and clarity
+ Attractive design in white has attracted many positive comments
+ Large amount of memory for running apps
+ Much more solid feel than previous Xperias
+ Also uses the Russian GPS sattelites, which gives faster and more accurate positioning than previous Xperias.
+ Very fast camera start up (relative to other smartphones)
+ About as big as you can go and still use it comfortably with one hand.
+ Generally stable OS
- The touch buttons at the bottom of the screen (back/home/menu) are easy to press by mistake when using the on screen keyboard. Pressing space in particular often activates the home button, which can be very annoying. Maybe a familiarity thing, but I doubt it since the distance between space and home is only a mm or so.
- Battery life is acceptable and on par with the Arc but this still isn't good enough. I want a full 24 hours, not half that.
-The phone is notably heavier than the Arc, which gives a feeling of solidness and quality, but also distorts clothes if you put it in a pocket.
- Data connectivity has turned itself off on a couple of occaisions. Easy to restart, but still odd.