Well..to add another observation for another car: I drive a 2005 E63 (645 Ci) with Bluetooth and BMW Assist. Upon purchase, I had a Blackberry 8703 with Verizon...which worked beautifully. The contacts list synced fine, but more importantly, the bluetooth connection NEVER had delays in dialing/answering via iDrive, never dropped a call, and the audio reception was very strong (hint, remember these points w/the BB).
Two months ago, I bought an Iphone and made the switch to ATT. To my liking, as soon as I paired the iPhone and E63, the contacts list loaded fairly quickly (795 contacts). The first incoming call pops up on iDrive, music mutes, I click "accept", but I can't hear them. "Hello? Hello? Hello?"...then finally the connection. Someone noted the 10sec delay earlier. But even AFTER the connection is established, about every 2-3 minutes the persons voice goes out...I hear a "clicking noise" for another 2-3 seconds, and then their voice comes back on. The person on the other end does not hear the clicking nor do they complain about my voice going out, but I hear all of it via the car. Is anyone else experiencing these short outages during a conversation?? I assumed it was just ATT, but maybe it's WiFi being "on" (I never turn it off).
Last night (1/18/08) I upgraded to 1.1.3 on the iphone. I just went to my car the contacts synced just fine, so the upgrade does not prevent pairing. I have yet to make/receive a call, but I will see if turning off WiFi helps that. If so, my world is back to Verizon-like (stable)...but with a much better device.
I'll keep you posted on what I see ....