there really is no cons to any aftermarket clutches. Depending on future mods and riding application, one clutch may be better suited for you than the other. Most people either go with the cvtech/stm or the qsc/stm. A full stm/stm setup is a bit of overkill for the average rider is more for guys that race and have built up motors. I think the cvtech has a slightly smaller one-way bearing than the qsc and gives it a little lower starting point, but the cvtech has been known to not be able to handle built up motors with high HP. If you're an average rider who wants to be able to turn bigger tires or wants to come out of the corners faster, than you really cant go wrong with either setup. cvtech, qsc, stm are all good and mostly comes down to how much you wanna spend. cvtech is around $700, qsc around $850 and stm rage3 starts around $1000 and the stm secondary is about $550.
