The camera is small and light, but still big enough for my hands. It has a good EVF, a big point for me, since I think a viewfinder is much superior to the display on the back of the camera. With the kit zoom, which qualitywise is ok, the setup is weatherproof enough to be used in the rain. According to the tests, the image quality is excellent, slightly worse than the best APS-C cameras from Sony and Nikon, but better than the Canon APS-C cameras. It has an excellent built-in image stabilizer, meaning that all lenses will be stabilized. Hence, on paper it almost seems like the optimal outdoor camera for someone like, possibly with the exception of the video capabilities.
With a small lens, the system is quite small.
The kit zoom is rather big, probably because it is sealed. The aperture is ok at the wide end of 12 mm (24 mm equivalent), but poor at the tele end of 50 mm. I would rather have a weatherproofed prime lens with a large aperture with a suitable wide angle, but seemingly no manufacturer believes that it is possible to sell such a combination.
In good light, the differences between cameras are not that big. The dynamic range does have some relevance, though, and here the EM-5 is actually quite good. Configurable highlight/shadow warnings makes it easy to keep the exposure right and there is some room to fix things in Lightroom. E.g. this picture would have had pretty much either a silhuette or a totally overexposed sky with a lesser camera.
The real test of the camera was the Vigu Survival course. You can see more pictures under the actual blog post, but below is an example of what is possible with it. I often find myself in situations where a tripod is just not possible to use, since there is no time for photography. You then have to work fast, and the EM-5 image stabilizer combined with a good lens certainly enables pictures that otherwise would be impossible. The below picture was taken handheld at ISO 3200, f1.8, 20 mm and 1/10 s. (ISO 6400 is still usable and the image stabilizer works with longer exposure times, though the success rate declines.)
A 100 percent crop of the above image, unsharpened. (Remember, this is pixel peeping.)
There was of course no doubt about the image quality in the camera, after all the positive reviews. The smaller sensor size is a compromise, though, and while it does not affect the image quality much, it does mean that it is more difficult to get a shallow DOF (depth-of-field). With the proper lenses it is still possible, though.
The video capabilities are lacking in two ways: There are no PAL frame rates and the codec is known for its low bitrate and inability to deal with complex scenes. My expectations were therefore not very high, so I decided to do a little test.
In this example, the video quality is quite ok, though the Vimeo compression made the video slightly jerky. I'll have to look into that later.
Finally, the maybe most important thing is that the Olympus EM-5 does have a high fun factor. I think I will be very satisfied with this camera.