Since only one or two people who actually have the 5800's responded, here's my two cents as a proud owner of a PNY 5800 Ultra.
1. The noise isn't so loud as to be distracting. The only time it's really noticeable is on start up, and that's 'cause nothing's else has wound up yet. I listened to the sound bits of the card running and feel they are a bit exaggerated. By the time the games start playing and it kicks in 3d, who cares?
2. I've very pleased with the scores of the card. I've busted 17k in 3d01, 7k in 3d03, and 51k in Aquamark. I've played all the latest games with all the eye candy on and the only gripes I had were the first few runs Halo before the patch came out. After it was patched, ran @ 1280 x 1024 (native resolution for my monitor, same for the scores posted above) with nary a hiccup. (For those interested, the stock speeds for the ultra are 500mhz gpu and 1000mhz ddr2 memory, I think I have slid the GPU up to 505, but as all i'e tweaked it , or felt the need to.)
3. I've yet to see a card come out that will convince me to trade up....yet. I haven't seen the value for the buck. Maybe the next generation, but when they come out, I'll reassess.
4. If Nvidia had waited and gotten the 256 bus instead of the 128 bit, and avoided all the flak over the fan noise, we'd probably be spanking ATI all the way to the barn!
'Nuff said.