I'm so glad to hear this...
I just received my Street Pilot III this last weekend!
I've been going back and forth on this very same issue - spend $2K+ on and Alpine unit, or ~$700 on a Street Pilot III. Another contender was the soon-to-be released Street Pilot 2610, which should run about ~$800 - $900 street price. All the positive reviews on the SPIII convinced me to try it out. I haven't installed it yet, but I look forward to a positive experience.
BTW, did you guys opt for the remote antenna??? I understand that for vehicles like the H2, it's almost a necessity.