Ive been looking at different motor/esc options. I was at the lhs and owner told me the higher the kv the faster you will go? One of his kits had a kv rating of 6400 and another at 7400. Now when I search through forums it seems most people are running a 3s on lower kv motor. I don't want to purchase a setup if I cant run both 2s and 3s???