ok im thanking about getting the merlin md.1d,are they over or underrated,they say they still make them in the us by hand,i am getting a us amp because i know how good they used to be they took a 1 ohm amd and ran it at halff a ohm for 24 hours if it didnt take u didnt get it,but are they still top of line amps, i mean better than mtx rf jl kicker etc,they merlins have a damping factor of 100 and the ax series of damping factor up to 1000 but they cost thousands,im not competlty sure what the damping factor is,but aint it the ability to control the sub