Also got the sports auto in my 125i, its great! Smooth in traffic and lightning quick to respond to paddle shifts! If you use the paddles without moving the gear lever into manual mode, then it'll revert back to auto after you don't change gears for a bit. Great feature if you just want to gear down for a corner. Only discovered after a while that I didn't have to push the gear lever into M/S then back into D to get it back into auto, so thought I'd pass on the knowledge.
Gear lever also moves back into normal position by itself if you put it into park from M/S. cute little trick.