Compared to its big brother Zuiko Digital 50mm F2.0 Macro 35mm has a higher magnification (1: 1). Also, the autofocus is felt a lot faster (and even not so roaring loud) as the 50s. Therefore you have to cope with a shorter working distance and because of the not very large aperture, the lens is what the crop in terms not necessarily the first choice for portrait photographers.
The lens is very sharp even at maximum aperture, and is a not there to hide from the big brother. Ever the lens is a price / performance wonder. For other brands you can grab for a lens with a similar magnification significantly deeper into their pockets.
Personally, I can only recommend the lens.
