I have TWO computers with win 7 ULTIMATE 32 & 64 bit, several xp32 bit, one machine with vSHITa 32 & 64 bit AND xp 32 & 64 bit, the xp boxes are mostly special purpose, the shita is software compatability testing, and the win7's are my main gaming comps, and I have THREE machines with MORE than 4gb ram ie 2 at 8gb and one 12gb, but I usually use 32 bit for it's better legacy support with 4gb & less ram.
AND I have been one of the forum members asking for 64 bit games for the reason you want to move the customers to 64 bit, ie no longer having a fairly small amount of ram to work with and having to pick & choose what to use and how do we trim the FAT off of this object, BUT please try to NOT waste the large ram available in 64 bit
harpo