simplicity of parts really. unsprung hub is alot easier to manufacture than a sprung hub. my clutch in my white car which is an unsprung organic material cost me 200$. a comparable stock clutch woulda been 325$ and a nice pucked or dual friction is 350-400$

but, the one i chose drives the best and will hold just as much power as the others. gotta love experience from trial and error. and ive had alot of error.