mtx amps with factory head units

i know mtx advertises that you can use hi-level input from newer factory headunits without any problems, but how do they actually sound with these "over eq'd" factory radios? I have a customer with an 07' CTS and they want to retain the factory radio. i know i could have them purchase a JL clean sweep, but im wondering how the mtx amps will sound feeding the factory hi-level into them?Mike Battaglia

Specialized Car Audio

Bensenville IL 60106

add the MTX reQ and it will sound perfect. that is the purpose of the reQ. After that, i put a TE601D into an 96 Monte with factory MP3 deck, tapped at the rears under the deck, sounds great. have to adjust the gain accordingly to not drown out the interior speakers