Honestly, I don't feel any difference when I overclock, yeah, in benchmarks I might see better CPU or RAM performance, but to be honest I've given it up, it was fun as an exercise, but I doubt the usefulness. So from my point of view it's not worth it.
Where you really feel a difference is fast drives, raid 0 with two or more SSDs really gives you an insane boost even if you just do the windows or motherboard striping.