My satisfaction with the 8800GT has made me lazy in keeping up with card comparisons. I'm also skewed thanks to Apple's insistence on calling my iMac's card a 5670. It performs noticeably slower than my PC's 8800GT, with other system specs being close-ish. (PC's Wolfdale vs iMac's i3, 4GB of 1066 vs 1333, 7200rpm drives) The comparison site I looked up showed that the 5670 has newer tech and a few nice things over the 8800Gt, but definitely lacks its raw horsepower. Maybe the 9800GT isn't as close to the 8800 as I'm assuming either.

My best advice is to not worry about spending *a little* more than you want in order to get a card you'll *love*.