Summits as POI on the Garmin sounds like a good feature to me! Easier to identify peaks and search for them in the field.
No, I've got 32-bit Vista as my laptop is just a few months older than the 64-bit Core 2 CPUs sadly. :-P Anything requiring PostGIS I just run through XP in a virtual machine and it works fine, though slightly slower. I'd be curious if anyone else got PostGIS running in Vista, but perhaps that topic should be a new thread...