Well, I don't live in MD, but the Cingular service sucks in NYC. The reception is much better than my sister's ATT (TDMA) V60 setup, but it's crazy how much network busy signals I get. Basically, when it hits 9pm, I can't take advantage of my 5000 N&W minutes because no calls can come in or go out. It takes about 10 calls before it works.
Rollover is nice since I've built so much that I won't have to worry about going over my minutes (it came with free 500 rollover), but that's the thing about rollover! The only people who will have rollover are the people who don't max their minutes. But these people will never utilize their rollover as it expires in a year. Those who max out their minutes every month have little to no rollover. Only those who talk sporadically over the year will benefit.
It also doesn't come with any free data service that I hear T-Mobile now offers (?) and I can't use my cell as a wireless modem because they don't offer free CSD service. I'm cancelling my service once my 1 year contract expires.