I'm running v10 and the overclocking and voltage control are pretty great features, but they need some more work.
I have a very strange problem. Most of the time, when I power on the rig and start Claymore, the cards appear to be clocked to the correct frequencies set in the .bat file, but they mine with the hashrate of stock clocks. I have to stop Claymore and start it again for the cards to mine properly. For example, at stock speeds (1265/1750mhz) they mine with 24mh and at 1100/2050 they mine with 29mh. On the first run, gpu-z shows 1100/2050 clocks but the cards mine at 24mh. When I restart Claymore, the cards are at 1100/2050 again but they mine with 29mh. Also, sometimes the voltages don't change accordingly, so every time I have to check the voltages with gpu-z, to see if everything is correct and this kinda blows the idea of having a fast way to restart a miner and have him up and running in no time. I know other people that have the same problems. Hope that this gets fixed soon, since this automatic overclocking from Claymore is an extremely helpful and easy way to overclock.