Back to the topic of AT&T and Verizon. I can't help much for the DE area, but I live in NJ and have AT&T.
In NJ, I've always had service, then in MA where I got to school, I've also always had service. The same goes for Verizon though. Out of everyone I know, its about 50/50 Verizon/AT&T. No one complains about their service. Basically just pick a phone you like, whichever provider it is on and stick with it for two years
I have a BlackBerry 8830. It's an awesome phone. Just picked it up a few weeks ago. Maybe you would want to give the BBs a look, but do your research and make sure they interface with macs, I'm sure they will.
As for the IPhone, from personal experience, they aren't all that great. They are nice, beautiful interface. The email updates slowly, every 20 minutes or so, web browser is nice, but so is the BBs, the touchscreen works well for everything except the keyboard that pops up.
Also battery life is just plain crap. If you use it during the day for anything other than being turned off, the battery takes a dump in about 6-8 hours. Worse if you play videos or listen to music, or god forbid check emails/surf the web.
I'm not an Apple fan by any stretch, but I gave the IPhone a fair shake, as did many people I know. Many of them say its basically a toy and if you want real usage, productivity out of it, all of them, save one person has gone back to BBerry. I tend to agree with them.
IPhone is riding the hype train into Craptown Station. Do you want to board that train?
Did you use the 1st or 2nd generation iPhone? I would think the 3G network would make Gen2 much greater than Gen1 when it comes to speed of network.
I was a Cingular customer so now an AT&T and I live in DE. I have great service in all areas across DelMarVa.