Yep using Vista ultimate 64 for three weeks now on a Nforce4 setup, with no problems all my old software (32bit) runs so smoothly, the only software I couldn’t get to work is a screensaver program ( the marine tropical fish one)
Hardware drivers have been very good the only thing I couldn’t get to work was my Speedtouch 330 ADSL modem ( the drivers for which are going to be released in March) so instead of waiting for Speedtouch I bought a Billion BiPAC 5200 4-Port ADSL2+ Modem/Router, and it’s far better and faster than the Speedtouch modem.
One pleasant surprise my old and trusty Samsung printer (ML1250) plugged it in and Vista 64 recognised it (nice one)
If you go down the vista route check before you buy that the drivers for your system is available, more and more are coming every day.
Marks out of 100, I would give Vista ultimate 64 (90) simply as it was so easy to install round 15/20 from when I put in the DVD and had no problems in the past 3 weeks .