Go with the JL. I don't think anyone will argue that it's a good amp. In my opinion, concept is overpriced garbage. The only reason I say that is any car I've seen that has concept has seriously underperformed. For example, in a db drag in my hometown, i beat a mustang hatchback with 2 concept 12's and at least 1000W rms to each sub off of concept amps, with my 2 10" rockford punch xlc's in a bandpass with a 100W....yes....50 watts per sub rms Punch 100a2 amp. And it wasn't even close. I hit 141.2 and he didn't even crack 140. I actually felt sorry for him, because he just dumped $6000 into his whole stereo. Mind you, that was in 2002, and concept hadn't been around for very long. Maybe someone can argue that they've improved. But I can't even give them the chance after that kind of a beating.