The pro 4 and Cyclone are both very nice cars and its good that the cyclone is virtualy pro4 in ereas so i already have parts. when it comes down to shaft or belt drive between my friends we descibe the shaft as on the edge and very quick, and then the belt as smooth and consistant, but when u look at the times there is nothing in it and at this time at our local track its a belt drive that is dominating. so between the 2 drivetrains dont think speed. thats only my opinion but any big name brand is competitive and they all nearly have small faults with someting but its up to what you personally like brand and drivetrain wise, hope this helps

dave, go the cyclone