What a god awful feature. Took my 2011 535IX M-Sport in for an oil change yesterday and they gave me a new 528IX as a loaner. At first I forgot it had the auto start/stop until the engine chugged to a stop at the first light. Reminded me of a rented Prius I drove a couple of years ago. Tried it for another two miles until I gave up and turned it off. Then all through the day I had to remember to turn it off everytime I started the car, annoying.
Also, the 4 cylinder engine in this car really sucks. Sorry, no other way to put it. It has absolutely zero power on the freeway. Might as well been driving my Dad's old Buick. Totally took all joy out of driving a BMW. All you need is to take a test drive in this car to make you want to spend the extra money for something like a M-Sport. Getting my car back again was like night and day.