greetings, just got my new iMac 20 w/2GB RAM. I ordered it w/the upgrade to 256MB VRAM but it only came w/128 (the std). Apple has offered me a refund for the upgrade (75-), plus an additional 50- for my troubles... So, is the upgrade to 256GB VRAM worth it? I do a lot of Photoshop. This system is a bit slow w/Photoshop at the moment, but the upcoming version of PS should fly. Anyway, take the $ and run? or send it back and get the 256MB? Thanks!!