My 335 felt fine afterwards, no issues. My buddy just said his brakes just didnt feel 'right' afterwards, like it had lost some bite or something. But he said that went away after a week or so.
The best part about the experience was to really experience the engineering capabilities BMW had put into developing these machines. I loved the low end torque in the 335, hated the no LSD no grip exits. I'm eager to see what it's like in the M. I'm probably going to the March 30th event too.
Hope to see some folks there.