Personally, I can't wait to get my XXX-S onto 64 pitch. Mainly because not only do I have a full set of lightweight 64P pinions and a ton of spurs, but I have really felt like I haven't been able to get the optimal ratio with the current gearing and stock motors. I think running mod gives you a little more give either way -- a 12T with a 6.4 or a 6.7 is not going to be a big difference -- but a Green 3 or a MVP can see huge gains/losses in a 3/10 change of the FDR.
I think I just became spoiled with my 64P gears on the Yokomos I have... finding the perfect final drive ratio was half my fun each day...
