Good day, I'm planning to buy the top end 27" iMac in the next month (I hope the 2012 iMac has been announced until then) But I am not sure if i should upgrade my video memory. Fyi: Currently i own a 13" MBP back from 2009 with 256mb of video memory on the nVidia 9400m. Can someone here explain what benefits i would have if i choose the higher configuration with 2GB? And maybe how important it is for Video editing or gaming? Thanks in advance!