Working in the computer industry (I was testing Beta versions of Vista long before they were released onto the market) I can assure you that Vista is currently useless for running music software.
If you don’t believe me, ask any computer tech and he will tell you the same.
Also go onto all the different computer music web forums, and you will find that virtually everybody that upgraded to Vista has now gone back to XP Pro.
BTW except for the big named software, very few Virtual Instruments work on Vista anyway.
However it’s your money to do with as you please, just don’t come complaining when you feel like smashing the computer with a hammer when nothing works as it should.
Regards

Bill