Thought I would share my M2 experience.
I had the pleasure of doing the 1 day M-school at the Thermal Club in Palm Desert this past weekend. It was a birthday gift that I did with my 75 year old dad. We got to beat on M4's, M3's, and of course the new M2's. There were 3 groups of 5 drivers (each driver gets a car, no sharing) and we would rotate between exercises. Wet skid pad, the proper line through a turn, 2 sets of lapping on a large autocross-like track, a timed autocross, and a rat race on the wet skid pad where you start opposite another driver and try to catch him. The wet skid pad was really fun and very tricky. It is polished concrete with water sprayers and it is super slick. The day finished with 4 instructors loading the students into M3's and drifting the entire course all bunched together. Not a big fan of drifting but damn it was fun!
I love tracking my "real" M2, but making lap after lap in the new M2 (with AC blasting) was really fun. Tons of power, huge brakes, double clutch tranny, and lots of rubber! The M2 was especially tossable vs the 3&4. The school is a little pricey, but I would highly recommend it...plus you get a discount if you are a Bmwcca member.