I go after market tbh,
The DSP system in my M Coupe is pretty poor for the money BMW charge, of course you get the integrated screen, but sound quality is poor
The bass is muddy and the overall sound lacks clarity
I'd much rather have a decent Alpine head unit and a matched set of speakers installed by a decent company.
Looking back I wish I’d bought a non sat-nav car, saved some cash and whacked a HU with a slide out screen with sat nav