For anybody that wants to know, I was one of them. I have this new head unit hooked up to two amplifiers. Rockford Fosgate 1000 W four channel amp and also a Rockford Fosgate 1000 W monobloc amp. I’m using the front and rear line out for the four channel amp and the subwoofer out for the sub amp. So far, I am very pleased with the sound of it over stock. Previously, i used an audio control LC7I but was never very happy with the sound. It was as if the volume for the four channel amp and the sub amp were never in sync with each other. I can’t comment on engine wine because the car is still in storage. I did have to pull the car out into the driveway and then back in the garage again after the install and didn’t notice any engine wine though��!
Edit. My previous audio set up had horrible engine wine and it drove me absolutely crazy!