you wanna make a statement, nothing like the Carrera (4)S w/ PDK to help you on your endeavor
I test drove the 6 series about 3 years ago - previous 2010 gen - nice car obviously and the m6 would add more plush and hp to it too but sort of lacks character ... something you don't get by ramming a powerful engine into a heavy, clunky shassis.
The new M6 comes with a significantly more power than the Carrera S but it is also much heavier, so as a result the acceleration is the same if not better in the carrera S w/ PDK transmission, on top of the Porsche being a much nimbler, better handling car (I mean let's face it, Porsche wrote and rewrote the book on superior car handling).
Of course tastes differ but all in all, I wouldn't throw that pretty penny for the M6 before testdriving at least 4-5 other alternatives and would leave the Porsche for last 'cause thats the only way you'd bother testing the others
One other thing - iirc, there was one curious shortcoming - imo at least - with the previous gen m6: it had really poor gas mileage resulting in a very short range before you have to refill. If you are spending north of 100K for a car then gasprices obviously arent gonna be a concern but I doubt you'd wanna a rent a parking space at the local gas station either

. With the new gen of M6 being even more powerful and just as heavy, I doubt they have fixed that issue unless they've practically doubled the gas tank capacity. Anyways, something to keep in mind