There's no point in upgrading on xp to get a few seconds better loading time and slightly faster switching.
When your talking about less than £30 for the upgrade hell yes there is! And those "few seconds" mean i now usually load into a BF2/COD4 map before the other players which in BF2 is certainly an advantage for vehicles!
Well for me 32XP ran better overall with 4 gig (3.25 actual) than with 2gig.
I totally agree and 4GB = no hanging.