After having my BOSE for the last couple of days, I definitely don't care - the BOSE is excellent. I'd imagine the B&O will be technically better, and at 705W is louder - but not so much better that most non-sound engineers are going to notice, and who the hell has turned their radio up to full and gone "that's okay, but it could do with being a bit louder?" 705W is more than you need in an large living room, never mind the inside of a hatchback.
If that BOSE system isn't good enough quality for you, you're not using high enough quality audio, it's as simple as that. I use lossless files ripped directly from CD, and it's as good sound quality as any I've ever found including my 500W B&O home system (which never goes above 60% volume, I might add)
I wouldn't turn down the B&O in the new one, but I really don't think it's an improvement to shout about. The MMI in general looks good, though - and I wouldn't mind a little easier control with the MFSW