Vista DOES suck. If you're thinking of trying out the DX10 features of Acceleration/sp2, here's a little warning for you: It's a quagmire.
These are the casualties so far, aside from my sanity and general well being:
Vsync - totally down for the count. Even nhancer can't get it going. My eyes hurt.
AA&AF - erratic at best and performance sucking
Stuttering - you can have 2 flavours, continuous or all in one big lump every 30 sec, your choice.
Administrator mode - don't run *everything* in it? Kiss your track-ir goodbye.
Graphical glitches - just way too many to even begin to mention, sound too.
Going back to XP tomorrow. If you're going to try Vista, save yourself some headache and do it dual boot.
If sometime in the near future MS and Nvidia get their acts together on these bugs then I'll try it again. In the meantime, good riddance.
-Lotus (FSX's biggest and most thoroughly frustrated fan)