That's a pretty big downside surely
Part of an M car has always been its character, the noise and how that noise gives a sense of occasion whether you were inside or outside the car, especially at higher rpms. Look at the E30 M3, not a particularly powerful engine, nor is it a particularly well handling car either, but it makes a great noise, and everyone raves about how it feels/sounds. The same applies to all M3s after it up to the E90/E92 v8. You could hear any of those from round the corner and you'd know exactly which one it was. This is no longer the case with current M cars.
And that's where the problem lies for me (and many others it seems). The eco brigade have forced manufacturers into turbo charging to reduce emissions. It seems only AMG are capable of blending the two together without having to produce synthetic sounds through the speakers.
You say the '17 M3 handles so well and has exceptional acceleration. This might be true, but the same applies to many modern cars, especially hot hatches like the A45, and that's a 4 cylinder! The thing with an M is that it should have a character that has always been associated with that badge, and to me, that character was lost once the N/A engines were dropped in favour of turbo ones. The new cars are really fast, but at the expense of character. BMW are in part to blame, because Mercedes has shown that you can have the best of both worlds, just BMW chose not to go that far ahead. IMO the new M3/M4 look amazing, but they don't sound how they look.
If I ever change my car to something newer, then it probably would be an AMG. I don't like the modern BMW exhaust notes, and the engine sound just doesn't do it for me either. The closest to decent sounding so far has been the M2, which sounds quite a bit nicer than the M3/M4, but I still can't get on with the back end styling of the 2 series