i think the main reason is the coil front they say you can feel more, works well on smooth tracks, and supposedly acts qucker but 1/2 the guys run 4 bar and the other half run coilovers..... coilover seems to be most popular out in the midwest i spoke to a couple guys out there and they say its because most of them run a 2" midget front axle because its more heavy duty king pins and etc because of rougher tackier tracks they were breaking the lightning sprint spindles and king pins , and they come set up for coil overs? so the real answer is probably preference ..... in ny we have guys that win races with both setups