Well. A friend of mine who is totally against Cadillac, and just does not get it (there are plenty of those around), who basically won't compliment anything about it, thought I had a remastered copy of a song we both like (Beatles).
He was so certain of it, until he made a copy and played it on his systems.
He said every car should have a Bose system.
The reason his ear was so keen on the difference, is that he is something of an audiophile.
Bose's philosophy is to recreate sound in the most natural and real-sounding way possible. They are so anal about their reputation, that they don't sell car stereos or speaker systems (unless they're replacements), because they design the system on a case by case basis. They fine-tune the acoustics to the enclosure.
I know I've gone through my phases of ear level tweeters, and of Bass boost, decreasing midrange for a cool, albeit artificial sound, but honestly, I really enjoy the BOSE system in my car.
Granted it may be impossible to impress others by playing it so loud that the folks at the grocery store look at you as you drive in the parking lot, or the kind that makes your neighbors want to call the police when you wake them up at night when you drive off in your car.
There's something about the Bose system in my car, that gives it just enough bass to feel it and see it (the rearview mirror vibrates gently). It makes me smile.
It even makes those friends that do not agree with a Cadillac at a younger than traditional age, green, if they're audiophiles.
If you want more bass, purchase an active subwoofer. I've heard the Bazooka is decent, and you can splice it in. If all you want is the capability to play CDs, then purchase the CD changer on eBay. So what if you have to load it? It beats paying a buttload of money to either replace it or upgrade it to the one with the headunit.
My unsolicited $0.02
Edit: Bose is so anal that they sometimes don't even offer a tone adjustment or graphic equalizer--why mess with such a close representation of "real," they think. No fancy equalizers on any of their products (to my knowledge, or they are rare if I'm wrong).