i'm thinking about selling my 128mb 9800 pro to my friend for about $200 (probably less not sure what the going price for a used is) and buying a 6600gt . i know i'll have to spend more cash so i wonder if it's worth the difference. i'm an nvidia fan, but when i was building my computer some time ago, the FX was crap, so i went with the ati.. so now with the 6 series it seems like a good time to go back. any suggestions?