Bluetooth, imo, works sporadically, is a pain to setup, and your entire ear aches at the end of the day.
Plus, you look goofy.
I don't use mine, and have no idea where the earpiece is, good riddance.
Pairing is really an easy process, and really only needs to be done once, newer versions of the protocol will make it even easier, and their working on upping the range from 30' to 100'.
It sure beats having a wire attached to the phone that gets caught on clothing or whatever, and a lot of states require a headset if you're using it in the car. If your phone supports it; voice dialing (saving a voice prompt for an address book entry) makes it easy to use, particularly when you're driving; have your hands full, or your phone is in your pocket, purse or where ever.
Dunno about Bluetooth, but my best experience has been with local/regional providers... Burned by Suncom, burned by Cingular, burned by Alltel, but here in KY we have a very good, very responsive company with excellent rates--Bluegrass Cellular. I have other than the activation month, not had a single month where I been slammed with overages, and that was due to a lot of extra phone calls relating to a move. I have few areas that I can't get signal with them, and in my job too many areas that Cingular and Alltell didn't have coverage. I can only assume other areas have similar regional outfits, I'd go with them... If in your area the national companies are the best thing, take my advice, if you consider Lets Talk, DON'T... Much of the charges that burned me with cingular were related to my dealings with them...