It's tough to communicate how good or bad an audio system is- so I thought I'd just tell you how it compares to other cars I've owned. Perhaps some of you will have heard those. For reference, I've been an audiophile since my teens- even owning Quad Electrostats.
What usually disappoints me in car audio systems is lack of high-end (treble) and clarity, lack of instruments separation and muddy midrange. I typically find car audio to be either terrible, "tolerable, but only because no other option", or "good- I like listening to this".
2014 BMW 640i vert with mid-range "premium hi-fi system" - "tolerable"- not as good as a good Bluetooth speakers
2017 MB E350 with mid-range upgrade Burmeister - "good"! - really impressed!
2019 Porsche Cayenne with mid-range upgrade "Bose Surround" - "tolerable"- (barely) I was looking into replacing treeters, poor high-end
2019 Audi e-Tron Prestige with Bang & Olufsen - "good" (not as special as MB Burmeister, but quite good"
2022 BMW iX Harmon Kardon (test drive and dealer audition)- "GOOD"- the best audio system I'd ever heard in a BMW- as good as MB's Burmeister I'd had before- quite relieved I would like listening to this particularly on better sources than XM
2022 BMW iX B&W I bought- because I took over a pre-existing order. New Classification- the best audio system I've ever heard in any car, and probably the best audio system I've ever had at home or in a car. Yesterday I heard (for the first time) the guitarist's fingers sliding up the strings on the fretboard on a Sarah McLauglin track I'd heard hundreds of times before. Remarkable detail. Bass, mids and highs are outstanding. Definitely deserves a better source than XM- Spotify good- CarPlay Apple Music "lossless" recordings fantastic.
In sum, I'm glad I've got it. If it ever resurfaced as an option for an XDrive50, I'd get it. It is not worth it for me to get an XDrive60 to get it. And if I never heard the B&W system, I'd say "with Harman Kardon, finally BMW has put a really good-sounding audio system in a car, it sounds fine"