Ok, so I've now been able to do some proper benching comparisons, and the 4870 is showing to be on top... but not by much.
I first tested the 8800 GTS with no OC settings. Crysis was averaging about 17 FPS, and I got a 3dMark06 score in the 9800 range.
I then OC'd the 8800 GTS to the values I mentioned before. Got about 19 FPS and a 3DMark06 score of 10300 range.
Then I did the same with the 4870. I got about 25 FPS on Crysis, and 10600 range on 36Mark06.
Previously, though, I had gotten 29 FPS average with Crysis, almost the same settings, and 18000 score on 3DMark06. When I switched mobo's, that obviously got rid of my CPU OC settings, so right now that is at stock, but I somehow wonder if my CPU OC settings really contributed to such higher scores. I really wished I could have done this test on my old mobo, but now I'm back to square one with my OC settings.
With all that said, I'm not all that impressed by the 4870, I feel it's barely performing better than my 8800 GTS (but at least now it IS better, whereas before I'm pretty sure it wasn't). I feel that I would have been better off just buying another 8800 GTS and running SLI.
Looks like I'll be spending a lot of time over the next week tweaking and benching.
IMO you should have stayed green, since you have an SLI board.