I upgraded my machine to vista, but, as you pointed out, Asus has next to no support for Vista yet, and there is a major unresolved driver issue with Creative Audigy and Audigy 2 cards that causes random reboots, so back to XP I went.
Rumor has it that SP1 will be in our hands in beta form by december 31 of this year, probably best to hold off until then would be my guess. The only way to get Vista working "100%" is to buy it preinstalled from a large OEM