IMO, the performance benefit with OC is not really worth the risk. We have no direct way to measure CPU temperature, and there is no ventilation on the phone. It's very easy to kill a chip like that.
I've been working with Dirrk and JT since day 1, and I can tell you Voodoo is 99% of the way there (at least lagfix). This is a true lagfix, unlike RyanZA's method. This is where you'll see the greatest performance increase.
JT has a great new function that he ported from the Droid 1 where you can dynamically change the OC values. If you really have to use an OC kernel, I would recommend that one so that you can go back to stock with a simple change of a config file, and not having to reflash.