AT&T Tilt
The AT&T Tilt has been great. It's a really nice phone, good size, display, etc. All the reviews on the web have been pretty much right on (I haven't looked to much at the ones on Amazon). I like Windows Mobile because it can multitask (I switched from a Palm Treo 650) and it has lots of apps. It requires a lot more button pushing to get the same stuff done than the Treo, but it's much more reliable at email (especially with the direct push) and web surfing is better than Blazer, although I can't get Opera to work. I sometimes miss the Treo's keyboard -- the slide out keyboard is fine on the Tilt, but the Tilt's keyboard feels mushy compatred with the Treo. Also, the battery life is kind of disappointing. I'm not sure if it's how I'm using it -- I get push email from work and it vibrates the phone every 30 minutes or so. But if I don't charge the phone at work, the battery is down to about 20% by the time I get home. I usually just bring the USB wire to work and plug it into my PC there to charge when I'm at my desk.

AT&T's network has dropped a few calls in places where my old Verizon network was flawless, but overall AT&T hasn't been bad. The data speeds are good where I live (Brooklyn, NY, in the 3G network), and the Windows Mobile apps I've installed have been great. Microsoft Live Search and Google Maps work OK with the GPS. In an urban environment, it sometimes has trouble acquiring the GPS signal. Once it locks in, though, Live Search works great -- beeping warnings when I need to turn and showing my progress on a moving map.

The only real problem with my experience was that the unlimited data plan I ordered through Amazon didn't appear on my AT&T plan. I discovered this while porting my number. It took about an hour to fix, but AT&T retroactively added the unlimited data plan to my bill. I haven't seen the bill yet, but hopefully it was fixed.