I used the M2 with its 235 specific sport springs on the track today.
I was using Hankook Z221 semi slicks. I was confident these tyres would show any shortcomings these springs have.
The group was made up of a lot of BMW track cars as well as a couple of M4,s and a lone C63.
Short answer is I will be keeping these springs.
Car was stable everywhere, minimal bodyroll and no bottoming out
Times are on the link below.
http://racing.natsoft.com.au/results/#2