I ride an RM250 and will take a two stroke over a 4 stroke any day!! If you break it down yea the four stoke is faster topend but the low end i will take my RM. The both have amazing get up and go but the hole shot goes to the RM. If you ride well enough to hold of the four strokes through out the rest of the race ther is no problem. It is all about the rider. I would rather have my RM and that is that. I just think that 4 stokes are geting way over rated!!!