My only problem with Vista (Built 2 Vista machines so far this year) was the most recent build last week - I tried to reuse an older DVD-Writer which isn't vista-ready. Switched that out and all's hunky-dory :-)
The new PC is nothing amazing:
AMD 64X2 4000 @2.10GHz (not got round to overclocking it yet)
Abit KN9 SLI Mobo
2Gb RAM
NVidia 8600GT
Was going to buy a 2nd SLI 8600 but may not bother.
I have 2x 19" flat panels - I use 1 for LoTRO at 1440x9000 with all settings ultra-high and the other for browser and Digital TV. Running both I have 0 lag.
Running DX10 on the Roheryn server is amazing.
Graphic details are finer, tree/object shadows, even more realistic water.
Again, all settings maxed, and still as whippy a display I've ever had even with TV running on monitor #2.
Nobody I know who understands basic s/ware & h/ware config has any problems with Vista.
Jump in. The water's fine