I had my head milled .030 a couple years ago. I run mostly 93 octane w/o any problems. I have a stock 2000 that is pushing 150 psi on each side at 300 ft asl. If I have the extra money, I will run 50/50 mix and it seems to run a little better. The only problem I have had so far is that I blew a head gasket last weekend riding, but nothing else so far.
I feel that this is a good mod to do at a low cost. Make sure that you have your squish band recut when they shave your head.