Both very good brands plus they both have very good subs and amps. If your talking amps I would go with rockford just based on quality and with subs its a toss up. Kicker's best sub I think is the solobaric L7. If you can push enough power to these, they will really pound. Rockfords best subs so far are the Power subs T1s and T2s. The T2 sub is just crazy when you can push the right amount of power to it. Only bad thing about the rockfords is that the power series subs require quite a bit of air space in the box, so if your going to have one of these, your box will have to be a little big. My buddy had 2 in his suv pushing about 5000 watts and they blew the windsheild right out of the seals. The only real answer is how much you want to spend because these brands are pricey, for good reason.