Don't like it. I keep it off. I tried it once just because I like to push buttons. With my Akrapovic exhaust it sounded like I was stalling the motor at each light. Besides, any benefit gained is usually quickly lost when I floor it from one light to the next.
I have been thinking about putting a Hybrid logo behind the M3 symbol just to mess with folks.
2011 Le Mans Blue M3// Black extended Novillo w/ Blue Grey Aluminum trim/DCT/ZTP/ZCW/ZPP/ZCP Premium Sound ///Akrapovic Evolution Exhaust
2012 Le Mans Blue 135i M Pkg DCT
2013 Ford F150 FX4 Supercrew