This is not a real review from a technical point of view, but I thought I would post my initial impression. I purchased a used adapter from B&H. Pros: Sharp images Good color rendition Nice bokeh Cons: Slow auto-focus Lens hunts unless subject and background have strong contrast Tends to focus on closest object as opposed to subject (could be a camera focus issue) Slow AF makes shooting moving objects a challenge I was pleased that I could get acceptable hand held shots with a fast shutter speed despite the fact that this is a 140-600mm 35mm equivalent. The slow AF is frustrating but, once locked in, the results are quite good. This lens is better suited to static objects or very slow moving subjects. A few sample photos are attached. In one of them you can clearly see that the camera focused on an object in front of the man on the cell phone even though I had the single area focus on his face (at least I thought I did), and I was using AF tracking. I would be interested in experiences if others with this combo. Also, would I be likely to have the same slow AF problems with other 4/3 lenses?