I'd love a chance to drive a 1M. I have a 135 now and have an M3 on order. The engine in the M3 is what sold me. That car is just an absolute joy to drive. I don't care how good of a tune you put on the N54 it just doesn't have the kind of response and amazing sound of the S65.
With that said, I can only imagine how fun the 1M must be to throw around a track. If I was a bit more of a track junky I prob would've gone for the 1M. However, I do one or two track weekends a year and the M3 is just awesome for a daily driver and it's no slouch on the track.
I hope someone in STL with a 1M will let me take a ride in the car with them.