This is an issue for MT6 N55 cars too. I had to sell mine after BMW updated the DME software & introduced throttle lag. IMHO the car became dangerous to drive.
Current: 2011 F20 120d SE & F21 M135i
E90 335i, 2010 Alpine White N55 135i 6MT, 2009 LMB LCI N54 135i - Cobb tuned!, 2010 F10 530d SE, 1986 E30 318i,1981 E21 320i Auto