At the risk of resurrecting an old thread - just wanted to say I'm getting this setup from James and having the guys at bimmerworld do the install/setup. Can't wait to see the results! I have a DE on 9/12 on the full course at VIR so I'll be able to post impressions at that time.
I did an event back in June on this config at VIR so I think I'll have a good reference point for commenting at least on feel. I don't keep up with lap times so I won't be able to provide empirical data on benefit. Besides, I hope to have a PFC front brake kit on by that time too so having two variables would probably make changes in lap times less relevant.
'15 M3, '16 911 Turbo S Cab