If memory serves correctly this lens is the fourth one in the short history of micro-four-thirds lenses with the focal length of 40-150mm and a maximum aperture of f4.0-5.6. The "R" designates that it is the version with an aspherical element and an "HR" element. It's one of Olympus's "high grade" series of lenses (according the the fact sheet on B&H Photo) so I think you can expect that it's not a bad lens. Time will tell but my early shots, wide open, seem sharp, detailed and nice.
So, why did I buy a cheap, kit class 40-150mm instead of the new, super premium f2.8 "Pro" model from Olympus? I'm booked to shoot two different conference/events in the upcoming week and I'm torn between shooting with the (much) heavier Nikons or the much more convenient Olympus cameras.
If I chose the Nikons (two D610s) I would want to use an all purpose, all terrain lens that covers a wide range effectively and then bring a longer zoom for just in case. If I choose the Olympus cameras (two EM5.2s) I needed something longer than the 60mm Sigma or 60mm Olympus Pen FT f1.5 lens to get images of speakers on stage in a giant ballroom. Since I rarely need longer lenses for the Olympus cameras and because I see myself doing more and more commercial work with the Nikons I wasn't ready to pony up a small fortune for the premium Olympus optic if I thought I could use something less pricey and