You mean reclocking, not overclocking. We would like the latter too, though, we don't even have it in the proprietary driver.the performance is still a wreck due to lack of overclocking.
Engine reclocking (GPU) is planned for the coming months, but don't expect memory reclocking (VRAM) for at least a year... the PM work is delayed by Maxwell support.
You're calling them a "Best bet" in the title? When we have a 5× faster proprietary driver, which also manages to be more stable?