My old phone would take about 2 minutes to "update phonebook" via bluetooth, but my droid X only takes about 2 seconds, but I don't have a lot of phone contacts. I don't know if it tries to import facebook contacts into the blutooth phone also. I'll need to try that.
I play music, get turn-by-turn, and answer calls through bluetooth on my car, but I've never noticed notifications going through bluetooth.
The only real problem I'm having with my bluetooth connectivity is that I can't seem to get the volume up loud enough for music. I don't know if that's a Droid thing, my sync software (media monkey), the doubletwist droid client, or my bluetooth. My bluetooth volume is at max level, my droid media volume is at max level, and I have media monkey transfer the files with a 110 volume level rate, which is plenty loud on my PC. Maybe doubletwist, and the default droid music player doesn't recognize volume levels in the MP3 data?