The quality is nice! Not night and day but you can definitely tell the difference in the mids and highs! Clarity is quite obviously advanced than the stocks.
I wanted to change my subs in the door too because the were getting distorted alittle when I turned it up.
The technician went and turned off LOUDNESS on my deck and it fixed it!!!
also, make sure if you're booking your iPhone upto your car to turn off EQ. It ruins the sound.