I love this lens. It serves 3 purposes. And it is small too, just mere 300 grams or so.
Firstly, it's a macro lens. Based on the specification, it can do 1:2 magnification. Roughly means, it can frame up to 36mm by 27mm. That's quite a good magnification, considering the size matches a Full Frame 135 size sensor.
Secondly, it's a fast lens. The F2.0 maximum aperture ensures its capability to shoot in low light scenes. The above shot is rated at EV2, or F2.0, 1/20s, ISO2000. Typically EV2 is like shooting a total eclipse of the moon. That's low light!
Thirdly, it's a portrait lens. It has a telephoto angle of view similar to 100mm in 135 format. The bokeh of this lens is excellent, along with the razor sharp performance. It may pose a problem with skin details, but better be sharp than blur.
Well, there's no perfect lens. Optically, this lens is flawless - no problems in matching the Zuiko Digital ED14-35mm f2.0 and ED35-100mm f2.0 twin zooms. However, the 50mm lens suffers with Auto Focus performance. Unlike the 35-100mm lens that has a focus limiter, the 50mm does not have it. And considering it is a macro lens, the focus performance can be a real nightmare. Miss focus, and it will travel to and fro such a long focus range that is highly annoying.
Despite this one flaw, I love this lens.