The newer Carrera S vert will run 12.0-12.2@116-118 mph WITHOUT the Porsche Performance pack (which is an additional 30hp).
I like the new M6 and it's wicked fast (Inside line did 12.2@119) but i'm afraid they are just big/roomy sofa's compared to Porsche's.
They are amazing performing machines, and light machines at that. People complain because the new 991 loaded is a 120-130k car but it's a significantly better car in every way by large margin (even compared to the GTS).
I'm really impressed with the 991, it's a world class sports car and does a lot for what it puts on the table