Is Is It Better To Use 8800gtx Than 9800 Gx2 ?

I have currently as you can see in my system specs the 9800 gx2 card which has 2 gpu's that add up to 1gb memory when its in sli mode. My question is is it better for me to use my 8800 gtx then the 9800 gx2? both use pci express but the 9800 uses the pci express 2 or x16 whatever it is. My mobo only has pci express so im not really getting the full power out of the 9800 gx2 as it is. Looking for a opinion if i should change out for the 8800 gtx. Planning on a new build in a couple months anyhow with all updated parts. But for the time being i was curious.