OK, don't shoot me ...
I just switched over the BMW X3 (30d Msport) after many years of driving those dammed RWD Merc C-class. I had the premium sound system in those, which used to be BOSE, then switched to Harmon Kardon.
I got the premium system in this new car, and I must say (contrary to most opinions above) that I find it quite splendid. I listen to a variety of music, from classical to hip-hop. Although I didn't find a system yet that can get down low with something like LFO (that's going back some years), it really does do a good job.
Incidentally, I did use the setting for the EQ. I found on this site. In the past days of spectrum analysers and graphics equalisers, I always found that slightly smiley face curve to the settings gives a good output.