I have used this sim in Vista (32 bits) and in WIN 7 (64 bits) and it worked flawessly.
If you like tanks, serious tanks sim, this is surely the sim you want.
From what I have seen most of the "perfomance issues" are sorted out after some tweaking, in some cases a proper configuration of your video card settings.
The Sim in my opinion is not expendive considering that this is really a sim with much more behind it than just some graphics and campaings.
Proff is that despite not having the "latest" graphics in the market, it has a long time loyal comunity and it is still selling.
However I just want to point that if you are looking for just casual game, then maybe this is not what you are looking for.
But if you are looking for a military tank simulator, there is none better avalaible.
