I 'know' one of those Tuningwerk guys from the German 1series forum. They have/had a 1M running 640 crank bhp and afaik for a trackday at Hockenheim they tuned it to 740bhp. N54 basis. But it became rather undrivable , the way I read it.
So this is a nice excercise what we can expect from the (if) upcoming M2.
A good car needs good brakes, a real limited slip diff, a nice chassis, good steering and plenty of power( preferable to the rear wheels ) plus if possible a manual box
This rather expensive thing better be faster/ better than the stock 1M because about 80bhp more on tap
Furthermore I wouldn't throw 30k US $ into an original 1M myself, but I bet it will be the better car to begin with, because 1M's basis is more Motorsport inside than a M235i in the first place. N54 is easier tunable thus cheaper to do so.
But I like it. Minus the rear wing
Cheers
Robin