After living with the system for the past couple of weeks I have to concede that I do like it better than the system on the A4 that this F30 has replaced. As pointed out above, the +/- keys control the system "intensity" level when in auto mode which is perfect for maintaining temperature but getting a little more cool air into the cabin on a hot day for example.
My CA also gave me a useful tip which was when you get into the car and it is extremely hot, just hit the Max AC button and give it a couple of minutes to vent all of the hot air from the cabin, and then you can go back into regular auto mode.
With my A4, if it was hot outside and I set the climate control to automatic, the system would be absolutely blasting cold air at a really high intensity level... with the BMW climate control I can adjust that intensity level to a level of my choosing, which I like.
** Removed - Tim330i **