So, I just got my car back from Eibach USA (in Corona, CA).......They used my car to try out their lowering springs for the F10 550i. The claimed drop is 1.0 inch in the front and 0.8 inch in the rear. The ride seems firmer yet still retains stock like comfort. I kinda wish the drop was lower, but then this is with the stock wheel/tire setup. I hope to get some 20in HRE's, so maybe the gap will be less between the tire and fender.
Before (Stock)
After (Lowered)