I have had this lens for a few months and have tested it against a vareity of legacy lenses and consistently find it better than all of them. I tested it against the Pentax-M 100 f2.8 and the Olympus had equal resolution and less CA at comparable f-stops. I also tested it against the Konica Hexanon 135mm f3.2 and the Olympus is has far better resolution, nicer colors, and less CA. Contrast was also better in all cases. Because the olympus barrel extends so far, it also has excellent bokeh at focal lengths greater than 100mm. Reviews say this isn't a pro lens. Some complain it is too plastic and light. Others complain that it can't shoot f2.8 or f3.5. But for a lens that sometimes retails for $99, weighs less than 120 grams, and shoots better than most of the best legacy lenses in its upper focal range, it is am amazing tool to put in your bag. I picked up a Super Takumar 135mm f3.5 on fleabay for $10 and will test it when it comes and report results. But so far, I'm not seeing a compelling reason to hold on to legacy glass in this focal range. Anyone have different experiences?