Great report. I've done several corporate events at the Performance Center.
I enjoyed them so much, I just did the full 2 day M School. I agree with your Z4 and M3 comments. I would love an M3, just not sure its better than the Z4 for "normal" driving. But it is better on track.
See my M3 laps here:
http://vimeo.com/37438079
I wish I had a recording of the instructor hot laps at the M School. Longer, faster, and MIND BLOWING compared to what they do at the corporate events. I rode with Mike Renner. They do the same course as the M3 laps above, without the chicanes down the long curved straight. Mike did that section 100+ mph, with the tail out ALL the way down that long curve and then snapped the car 180 degrees into the big right hand curve and kept the tail out the opposite direction all the way around it!
__________________
2020 X3M non-comp, Alpine White over black : Exec Pkg, ventilated M Sport seats, 20"s
2020 M2 Comp, Sunset Orange/Blk: Orange stitching, DCT, exec pkg, bicolor rims
Gone '18 M550i, '16 X4 M40i, '15 M5, '13 X3 35i, '12 335is, '11 X5 50i, '09 Z4 35i, '08 550i, 06 X3, 06 650i, '02 M5, '99 540i