Just installed the cdsp, it sounds outstanding! it went well over what I was expecting I haven't even EQd anything yet all I have set are the x-overs and have reset my gains to the cdsp and it sound 10x better than my old eq'd lcq. Not only does it sound much better, there is absolutely 0 feedback, noise, crackling ect. and is slightly louder than it was before. I would recommend this setup to anyone who is going for sq.
along with this I also have my factory radio hooked up to the cdsp, I have it setup so when I go to preset 4 I can still listen to my radio, use my 3.5 aux or anything else with the factory radio.