I had Verizon for 12 years prior to switching to ATT and the iPhone when it first came out and have never looked back. Last year I spent the night out in front of the ATT store when the 3G came out and plan to do the same on the 19th.
There is nothing that compares to it....everything else is a "wannabe", nothing compares to the iPhone. Yea, it cost a bit more to have but Apple has been pretty good with the updates and upgrades. I know it's not for everyone, but I would highly recommend it for people that like the "wow" factor, and won't be disappointed.
Besides....my favorite camping spot just got 3G, how can you beat that?