I have a Kill-a-Watt on 2 of the rigs.
Rig 1: 1.197GHs - 1,371,626 shares since GUIMiner Update
Rig 2: This doubles as my gaming machine and not for sale
Rig 3: 1.214GHs - 575,707 shares since last reboot
Rig 4: 1.196GHs - 1,369,556 shares since GUIMiner Update
Rig 5: 1.242GHs - 1,424,775 shares since GUIMiner Update (This rig has 3x 6870 and 1x 5850 - 6870s are running 299.4 Mhash and the 5850 is running at 344.4 Mhash) 803 watts at the plug
Rig 6: 1.203Hs - 1,378,239 shares since GUIMiner Update 721 watts at the plug
I am clearly not getting the 2.3Mh/w that quattro claims is possible, but I am within the examples on the wiki. I know I could tweak it a lot more to save a few watts here or there, but I am motivated by stability. I found something stable and stuck with it.