I have the 4/3 40-150 and use it via the Oly adapter. I can say am really impressed by the IQ, especially sharpnes and contrast. There are days in wich I do not take it of the camera. Actually I like it's IQ more than that of the original 14-42 micro lens. According to me it has one real shortcoming - AF speed. It is sensibly slower than that of the original micro lenses. But if you like the 40-150 mm range and you don't mind the slower AF I think you will be quite happy with that lens.