I... own and use the Olympus OM-D EM-5 as well as the Olympus EP-5 cameras (as well as other digital cameras) which are wonderful instruments. This new OM-D EM-1 is even better! Wonderfully built, solid but compact and light for a pro quality camera, I also purchased the optional battery pack because I like to have the back up in the camera. It makes the camera even better. The 12-40mm f2.8 Pro lens is totally awesome! This combo compares extremely favorably with full frame pro cameras from Nikon or Canon (and others). It weights a fraction of those bulky cameras and is much smaller with performance to match in almost all facets and superior in some. I expected a nice product and an improvement over the EM-5, but this EM-1 is even better than expected. It is also weather sealed, which is a nice feature. There are many reviews of this camera online and in youtube. Please check them out. If you are looking for a fantastic camera for pro use or serious amateur, you cannot go wrong with the Olympus OM-D EM-1