It's a bit too fat, yeah, but that would be a weird complaint, coming from me :p
Now, throw some R-compound tires on the M6 (like the Pirelli ones on that black edition merc) instead of the crapo-la Continentals it comes with standard and re-do the test...
I can just imagine the conversations between the typical corporate exec buying that Black Edition AMG and a Service rep... "Yes Sir, your tires are corded after 5,000 kms, we put 'em on there so that you can out-handle your buddy's M6 on the way to Starbucks!"