Matrix hunter is correct. Ive been doing extensive research into this. I absolutely cannot stand the 1/2 dead space that is apparent in the steering of the m240i. according to realoem.com....the m235i/240i is straight electric steering, not electric power steering. The m2 is electric power assist steering. The f22 is listed as AT-steering box ELE and the F8x is listed as Electric Power Steering Rack. It might be possible to recode the f22s to increase or decrease weight but i think the ultimate issue with the steering is with the dead space, I've installed a stress bar, it helped but still dead space, installed m2 control arms, helped but still dead space, installed turner motor sport monorail thrust arms, helped but still dead space. I do not notice their being a weight difference between the f22 and the f87 or f82, just a difference in how the f87/f82 has no dead space where the f22 it is completely apparent in. I believe that this is the "weight" difference feel everyone is describing.
for reference here is the link to the straight pipes review of the m240i. just watch the first 5 mins and they'll explain the steering.