I just upgrade the memory on my tablet pc and my desktop to 4gb each one, this is because the great prices i found on ocz memory, the dual channel really help a little with the speed, specially on the tablet pc (HP TX-2510us), also i found that i can use the serial key of windows vista 32 bit on the 64 bit version with no problem, so right now i got 4 gb and i am very happy with it, both computers run with no problem when i am working with lets say word+powerpoint+acrobat or any new game.
On latest games, on my desktop, everything run smooth, even better than in my windows xp (AMD Phenom x4 @ 3ghz and ATI 4870 OCX).
By the way i got windows xp on a second partition and only detect 3.2~ gb ram...
Sorry my english.