It's very useable but I wish the keys were a little less matte as they are kind of slippery. Also the top row is pretty close to the bottom of the screen piece so you kinda have to jam your thumbs up there to get the numbers. I wish there were little bumps or some kind of tactile thing on the four touchscreen buttons (back, menu, home, search) so they'd be easier to find, but I'm sure I'll get used to where they are. Also, it's very easy to accidentally dismiss things (like an alarm) when you grab the phone and I am sure it might be too easy to answer the phone. There's no end button and when entering contacts I accidentally called someone by pressing too long, and frantically trying to get back to the phone "app" was confusing. I wished there were a physical button I could press to cancel the call. Overall though, it's pretty awesome. The Verizon guy said it should be able to be used as a tether soon as well, which was the only feature I found noticeably missing from the comparison chart.
