My personal experience with OverdriveNTool has been fantastic. I used to use claymore's clocking and under-volting (AB can't under-volt memory) feature and don't know why I was getting very frequent GPU hangs and rig freezes.
I set all my desired clocks and volt in OverdriveNTool and then .bat which would set the clocks using my pre-defined profile silently on start-up (30 seconds delay) before miner application starts running (run the miner app after 30 seconds). I use claymore fan control on my AMD rig by setting target temp (-tt) and AfterBurner fan control on mixed AMD-NVIDIA rig.