Unfortunately I think a number of the guys run F103 or wide F104s which as you noted are faster but can only be raced locally not in any national event. I think the problem is that they are hoping just to get enough turn out even to have a class and are afraid that any rules might limit participation. As far as I know you could shoe up with a 4.5 turn brushless, $300 ESC and a 3 cell lipo and compete in there F-1 class.