I used to have Memphis Subs, a couple of dual coil M3 12's, for several years up until two Fridays ago when someone stole them out of my car.
They always sounded great and I never had problems blasting them. I haven't seen anyone else with any Memphis equipment around me as they aren't just sold anywhere so mine were definitely different. I'm actually planning on getting me another set of Memphis subs when I get some money now that I have a better security system installed. If they fit your needs, you should definitely get some!