Well... it's been a royal pain in the butt, but I've finally made some changes to my 8800GTS and I'm really happy with it all.
I needed to flash the BIOS of the card because last time I did it, I accidentally disabled temperature monitoring. But, my floppy drive is still not working, so I had to figure out how to make a bootable CD and get NVFlash to work on it. Let's just say it was a royal pain in the butt!
But after a few hours of confusion and headaches, I finally got it working. Now, overclocking through NiBiTor allows you to do something in the 8800 series you just plain can't do when you overclock in software via Rivatuner et al... you can manually set the shader clocks!
So, I bumped the shader clock from 1300mhz up to 1500, same as the 8800 Ultra. Obviously I don't expect to get quite the performance of that card, but I'm sure it's close enough that I don't need to sweat the $430 price difference. Anyway, current clocks on the card are 675 core, 1500 shader, and 975 memory. I actually did try bumping the shader clock up to 1600. I've found that you get roughly 1 point in 3DMark06 for every bump in the shader clock. So 1600 added about 97 points to my score, but it bombed in ATI Tool. No dice.
Oh, and by the way... I also took note of the card temperatures for the first time since I got my water cooling setup... with air cooling, the card had been pushing 80°. Now under full load the highest it got was 55°. Not bad! I expect the temps to be lower tomorrow because I'm actually going to swap my fans around. See, I looked up the specs on my stock Silverstone/Everflow case fans and found that they're the same RPM as the Arctic Cooling fans that cool my radiator, but they move a fair bit more air. So, I'm going to swap it around so that the Everflow fans are cooling the radiator, which should give me a nice temperature drop with no added noise.
Looking forward to tomorrow, when my new motherboard arrives. I just sold the EVGA 680i, and more than covered the cost of my new board in the process.