I don't get in modern BM's and Audis very often but when I do I find the ride pretty harsh.
Not sure there's a wrong choice in this sector, they're all excellent cars. It comes down to personal preference and whether you encounter issues with your particular car.
I rather enjoy the 900mile range of my current Audi A6 Ultra Avant
Would love an RS6 though
Actually one thing I would say is that Audi drivers seem to be taking the crown for most selfish road users, FWTW!
I know I can be accused of bias over this, but imo the E63 is the most underrated car (in the UK at least) in the AMG range.While on the subject of ride, I was seriously impressed with Bryan Allman's E63 the other day - I had expected Peter's CL63 to be exceptional, but even in sport mode the E63 insulated you pretty well, but not tried on the potholed roads round here.