I'm not sure what you saw run but I can tell you that a properly tuned Extech will hand a Jammin .28 it's arse! My EB Mods Extech will smoke anything at the track. I know I have the fastest mill out there. Unfortunately I am not the fastest driver. It accelerates like a brushless. Besides what is the sense in comparing a .28 to a .21? Sorry but I know the truth. Everybody is entitled to their opinion. But please don't make false statements just to start something.