I've been back and forth on these two lenses for my next purchase. A bit of my backround... I purchased an EM1 about 5 months ago when my first daughter was born along with the 12-40mm and 45mm. 90% of my pictures are of her. I know eventually I will get the 40-150 for the extra reach but I wanted to know if I'd be missing anything if I used the 40-150 for portraits over the 75mm prime. Size is not a factor in the decision. Thanks!