I moved from Nikon to Olympus. Your points read very strange: Cost: you are omitting the cost of the lenses. See how much FF 600/f4 will cost you compared to

I moved from Nikon to Olympus. Your points read very strange: Cost: you are omitting the cost of the lenses. See how much FF 600/f4 will cost you compared to Olympus 300/f4 Pro. Size: ditto. The camera body is half of the story. You need to compare the whole system with lenses. Compatibility: there is a gazzilion lenses made for m43 by Olympus, Panasonic, Sigma, etc. Video: The latest releases E-M5m3, E-M1m3, E-M1x are no threat to Panasonic but are perfectly capable video cameras. Even E-M1m2 was reborn with the new firmware. Some other advantages: Weather proofking—second to none. IBIS—second to none. Quality optics: Olympus pro lenses can be used wide open without significant loss of the quality. This is not the case for most of the high end FF lenses. Computational photography: Live Time and Live Composite are amazing. High-Res handheld mode is amazing. Live ND is a nice option. Starry AF works perfectly.