I just got the RAM unfortuanately 1 chip came as a dud, they are going to replace it, so right now I'm running on 3GB of total RAM ( the new 2 GB chip and 1 original 1 GB chip)...
and all I can say is WOOOOOOW, a massive difference..my Aperture Library (all my images are RAW and TIFFS some TIFF can be upto 70 MB for one image alone) loads at maybe 3 times the speed, Photoshop renders actions at least twice as fast...and this is with only 1 extra GB.
The computer responds also twice as fast when opening new apps...man I should have done this a while ago...but then again the RAM was twice as expensive a year ago...but man this is real shocker, can't wait until I get her running on 4 GB...