Definitely underrated, S6 did even better - 1/4 mile 12.1 sec, F10 M5 did 11.9 sec in the same review. Pretty impressive for $71K (base price) S6 as well as 4255 lbs. for V8TT + AWD with 17/26 EPA MPG.
http://media.caranddriver.com/files/...-e63-amg-1.pdf