Yes, there are a few. Some have made decent tests on 5850's and 5870's to find the sweet spot for lower energy usage while not compromising hashrate.
For 5870 I remember 1000/210 and 950/210 as one sweet spot for some. Basically make adjustments on either the core or memory until you get invalids then back off, modify the other until same, back off slightly. This would be the maximum you can OC/UC. Also, OC/UC depends a lot on which OS you are running, how that will be achieved.