If you do upgrade to Vista 64 just remember to switch off all the start up bits and bob's that you dont need with msconfig (cant remember the proper name for it!), this will speed it up a lot, oh and the bloody user account control thing as thats a pain (a quick google will show you what you do and don't need. If you tweek it a bit it becomes nice and fast, I find it nice and quick, not had a single crash or a problem with drivers (make sure that you can get all the drivers that you need for other bits and bob's too) other than my graphics tablet, the latest one form the manufacturers site for vista 64 didnt have support for the pressure, but I used the one that I got in the box and its working fine.

Have a bit of a research into any problems that you may/may not have with the MB, I had to switch the chipset over in the BIOS to use the 8gig, it could see it but only use 4gig switched it and its been fine since.

Other than that it's been rock solid with Maya 09 64 and everything else.

Oh yeah a back up or a dual boot wouldent hurt either just in case you do have problems.