After a few days of not very methodical, mostly random snapping with the 40-150, I think I am on to a winner.
Up front I need to say, the lens feels very low end. the zoom is stiff and the lens itself so light it is almost comical on a solid camera like the EM1, but that aside. the results and usability it offers are solid, even slightly impressive. Most of the images below were ISO 200 RAW files from the EM1 , except the last 2 (ISO 800 RAW).
It is amazing what you can get without even moving.