I've heard a few people say WinXP has a snappier reaction and I can believe that can happen in some cases due to hardware configs. However I'm running 2011 on Win7 and its all babycakes.

Maya crashes can be video card related. The hotter hardware gets, the slower it gets, until it gets to a point where it starts to malfunction. There's a min and max temp under which they should operate, if the room is nice and cool for you then its fine for the pc.