I use the Olympus E-M1 and E-M5 Mk II cameras and the 5-axis optical stabilization is better than the OS with the pro lenses from Nikon and Canon and it is very evident with longer focal length lenses, including the Olympus 300mm f/4 which also has OS. The electronic view finders on these cameras are excellent and so a cost savings in not having to use an external monitor or even resort to a hood over the rear display. ISO 6400 is usable with both these cameras which impressed me when I saw the RAW output on my monitor.