Most aftermarket head units out there can not compeate with the quaility of 1996 and up GM Factory units. Matter of fact only 2 or 3 are even Direct Fit units for GM large (din &half) openings. Of those, none look right in the dash, and they don't fit properly in some GM dashes.
GM Factory head units with a AMP and Aftermarket High End speakers can go over 140 D.B. and still sound clear as day.
I used to have a Conversion van (87 Astro). Was in my family from new till salvage. Over 330,000 miles (maybe 80K Highway). It came from the vehicle converter with a Aftermaket Radio, a panasonic if memory serves me right. It lasted all of 80,000 miles. The next after market radio lasted all of 20,000 miles. Eventially I got tired of swaping radio's. I finally went to a salvage yard, got a radio and wiring plug from a 87 Safari Van. Installed it (converter cut factory radio wires), and got years of dependible service.
Im My 87 Cavalier (which has a messed up counsel/lower dash) I have a
1989 Chevy S-10 Blazer radio. I have a small 40 watt (Peak)amp for my rear Poineer 150 Watt (Peak) 6x9's.Unlike some people out there. I like my audio to be clean, crisp, and distortion free. I also don't like my vehicles to look hacked up with cheesy radio adapters, speaker boxes and other aftermarket junk.
BTW: paying a small fee to get your radio unlocked once isn't stealing. If your too ignorant to write the information down and keep it in a safe place has nothing to do with a dealer. Charles