I got my 7900 GT yesterday. (XFX Extreme Edition) what a difference it made! even at stock.
I can now run pretty much every game I play at max settings (though I don't have FEAR or Oblivion)
so far I've got it to 560MHZ, with the stock cooler and at stock voltage (1.2V)
the cooler is also fairly loud, so now I'm definately going to get the VF900 when I can.
after I get the VF900, I'll probabbly volt mod it and see if I can hit 700MHZ
*edit*
3dmark05 actually runs at smooth framerates with my 7900. I used to get about 2-4fps, haha