Recently got this lens to round up my "travel light" kit, which consists of the EM1 and 17mm f1.8 lens. I had my first outing with the lens this past weekend on a family outing, and have to say that I am impressed. Of course I had read many user reports about the lens, all with positive opinions.
I have shot a mix of portraits of family members, plus a few landscapes of the countryside. The lens handles beautifully, and for landscapes, it provides some nice isolation of key elements. It is a 150mm eq. after all. And it is as sharp as it can get, and robustly built, no trace of optical defects. The added bonus is the IS on the camera, it provided me the freedom of roaming around without a tripod, and nailing shot after shot.
I will post some shots soon, as examples, but this is indeed a very fine lens.