it all depends on the game, and esp if you are moving to 64 bit, some games like FEAR 2 on 64 bit has minor issues, other can't even play at all at all (my old dos 16 bit game transport tycoon for example...) and needs other things like dosbox emulation.
Well, I can say that W7 work better that Vista, I was trying to play on VISTA Prototype, XMEN and COD and I wasn't able to play this game were running really slow. Just upgrade to W7 2 days ago and no problems with all 3 games they are running very good hope this will help you decide if you want to move up to W7.
I was no able to play Crysis on Windows Vista last nite i did install Crysis on W7 and walaaaaa it was running really good.. dont know what was wrong w/my W/Vista but it seem like W7 its working real good.. Only problem that I have w/W7 is that mozilla is not running good I read on an article that M$ is trying to control the market again its just time for some fox to get everything right.
I managed to get it working under Vista 64 but omg it runs too fast... or im just getting old lol
So it runs correctly under Windows 7 ? (looks like I have something to look forward too)
UT that is if your wondering wich game I have it and the map packs that came on CD's with some magazines