I've got a couple, and the only difference that I can see is the integral dipper. I'm sure that there are some hidden differences. I was told that if I plan on turning over 3600, to go billet. I've also heard that before the billets came out, that some were turning over 9,000 with them....with quite a few failures. Not all, mind you. I'm not willing to chance it, being that you can pick up a billet rod fairly cheap. JMHO.