I just test drove the 550i xDrive and Audi S6 back to back, and I must say the Audi felt much more athletic, had a better engine note, and better driving dynamics. I went into the day wanting to lease a 550i because the great lease MF/residuals, styling, and beautiful interior. However, now I feel at a loss. Would anyone who has driven both cars please comment? Thanks!

 

The 550 xi is sick. It is more a quiet beast. Change the exhaust and then it will psychologically meet your approval.
I just bought one coming from a 13 M3. And first ride home was crying.
The 550 is so smooth it feels slow. But it isn't. Put it in sport and run that bad boy and you will see a huge difference. It's awesome above 100