possibly. certain 8800's have another 256mb of ram than the top 9800 bringing it to 768mb ram total so it might run smoother with slightly higher framerates. i'll check the specs on the top of each and give my comparison
EDIT!
8800 Ultra vs. 9800 GTX+
8800 has a whopping 30+ gigabytes more bandwidth with only 256MB more ram, so i'm sure it would play better even though its a outdated.
newest 9800 GTX+ has 1GB of ram, so it would easily beat out the 8800 Ultra
9800 GTX+ w/ 1GB ram wins