Actually, the ride height difference between 195/55-15 and 195/55-16 wheel/tire fitments is only 12.7mm, since only half the difference in overall diameters effects the ride height.
I just went back through some old emails and found this from
Tech Man at MINI USA:
So, your recollection about Sport Suspension Plus is right on ... it's not any lower than the Cooper sport suspension. The difference in ground clearance is due to the 175/65-15 versus 195/55-16 wheel/tire fitments.