Not done the switch but probably won't be twice the car.I have owned non-M cars and M cars of the same series, ie, I went from an Z4 3.0 to a Z4 M in the past . With M cars you're getting everything that little more improved. Top end of everything (cars, GPU's etc) is never worth the money if you compare to the next model down, but it's not about that . If you want the ultimate of a BMW series then it has to be the M.
Well... courtesy of the folks on this forum reinforcing the lack of logic... I've just bought a BMW M4 Competition Pack! Yas Marina Blue with Silverstone Leather!
The numbers of course made absolutely no sense... but whatever, live once and all that... should pick it up on Friday! Be prepared for pics and posts