One point I like to bring up about Vista x64 and gaming,reminder really is that you can't run any 16 bit software/games(due to no 16 bit legacy support) so that may be an important factor for you.
There are ways around that like dual booting etc.. but personally I don't use or run any 16 bit software.
There are ways around that like dual booting etc.. but personally I don't use or run any 16 bit software.