Plenty of reviews here ..
http://f15.bimmerpost.com/forums/sho...157810&page=12. Some even stack it with RaceChip piggyback tune.
For me, there was a significant increase of power mid to top end, even in comfort mode. Just got back from Disneyland last week and often times I have to watch my speedometer as it was so easy to get carried away when overtaking a semi. Around town, I'm often in sport mode and notice a more aggressive shift points but not to a point that it'll jerk you or your passengers around.