After 50 years of photography from amateur to part-time pro, I have come to judge camera gear for what it can do for me. Outdoors, I photograph landscapes, cityscapes, flowers, and birds. At home, in my little indoor studio, I do some fine art studies and small product photography. I also do my own fine art printing up to 16x24". This year I did the impossible: I gave up my Pentax APS-C system and moved definitively to the micro 4/3. I now work with two E-M10's, one E-M5II and a good selection of Olympus and Panasonic lenses. I find the E-M5II to be an amazing tool for every aspect of my photography.EVF and LCD: coming from film SLR's, I am used to some beautiful pentaprism finders. The E-M5II EVF is very large and clear, it adapts to the brightness of the subject and, with its main camera settings display, it allows me to keep shooting and reset the camera without taking my eye off it especially with dynamic subjects. The LCD is beautiful, sharp and fully articulated. I regularly photograph close to the ground (i.e.: small plants) where this feature is a God-send. Even in the studio this is very handy. The Super Control Panel is visible on both the EVF and LCD and is very functional.Sensor: its IQ can compete with many APS-C camera sensors. Shooting Raw and developing in Camera Raw or (even better) DxO Optics Pro, noise is not an issue up to ISO1600 (my max ISO setting). 16Mp are enough for what I do. Even cropping down to 12Mp, I can upsize my files with Perfect Resize up to 800% without visible loss of quality. This gives me a 96Mp or 8485 x 11313 pixel file that I can print up to 28x37" at 300dpi. For static subjects and some other creative use, the High Res Shot produces moiré-free files with amazing detail, color fidelity and low noise which could be enlarged even further. I did test this feature and can assure you that it's real and mind-boggling.Image stabilization: it's simply the best on the market. The control is so fine that allows for a 5 f/stops stability gain and for the High Res Shot feature.Exposure: the EM5II has some of the best exposure metering in the business. Unique features include Live Time that allows you to monitor the brightness buildup of dark scenes and stop exposure when you like it, and Live Comp which is ideal for creative night scenes including fireworks, car lights and star trails.Autofocus: the S-AF is very fast and assertive. C-AF and Tracking could be better. I had to learn to manage the latter and help it latch onto the desired subject (difficult to explain here). I photograph mostly shore birds with the Pana 100-300mm zoom and find that personal technique is truly paramount. Some of the best action happens at take off and landing, events that I can predict. Here S-AF works just fine and lets me shoot sequences at 10fps. For total depth of field in macro photography I use the excellent Olympus 60mm macro often with focus stacking. I take multiple frames focusing from the front of the subject to the back and a number of intermediate steps. I import the frames as layers in Photoshop in a single file, apply Auto Align and Auto Blend and Photoshop creates a single frame with all the sharpest parts of the multiple frames (magic).Ergonomics: the camera is a pleasure to handle. It's small and relatively light but, at the same time, built like a small tank. It fits well in my medium-size male hands and the many controls are well placed. Some people complain that longer lenses unbalance the camera but I disagree. With telephoto lenses, I let the camera sit in my left hand at the zoom ring and this makes the whole system even more stable than with smaller lenses.Weather sealing: with all my shooting in heavy weather, so far I have had only one non-weatherized camera failure. Nevertheless, when I take expensive (for me) trips to places that I will see only once in my lifetime, a few hundred dollars more for weatherized equipment is a lot of peace of mind. To achieve effective weatherization, gear must be built with fine materials and tight tolerances. (added on 100715: I took the fisherman's pic at Montauk Point, Long Island, in 50mph wind gusts and a recurrent fine seawater spray. Once back at home, I washed the EM5II and 12-40mm f/2.8 lens with a sponge and that was it).Learning curve: I am an electronic engineer with a ton of photographic experience nevertheless it took me some time to learn this camera and its software (Raw High Res Shots can only be developed in Olympus Viewer 3). You can set the camera to auto and let it roll but people who want to use its advanced features should be aware of its complexity. You do have to read the manual cover to cover and, probably, do some additional research on the web. Then for some time you have to experiment with the camera in real life to get acquainted with its multiple features and controls. I happen to love this learning phase but some people could find it overwhelming. I would strongly recommend using Myset (1 through 4) to record your favorite settings for different shooting situations. This allows you to recover from any accidental camera resetting in a few seconds.Others: the camera grip (sold separately) is a useful accessory. It adds a deeper grip and a second battery, and can take an AC adapter which is great in the studio.Conclusion: I find that for my kind of photography the E-M5II is overall hard to beat. The excellent selection of lenses is another decisive factor to buy into the M43 system. I use the slower but minuscule lenses for maximum portability and the brighter Pro models for max IQ. I am attaching two studio pictures of one of my wife's jewelry creations. The first one is a typical Raw developed in Camera Raw with some sharpening, the second is a High Res Shot straight out of Olympus Viewer 3.020116: Considering the little money that I could get for the Pentax K5 I decided to keep it but since I got the Olympus bodies I have used it very little. In a medium size and very comfortable sling bag I can fit my EM5II and EM10II with short and medium zooms on them and there is still room for additional glass (such as the 60mm macro).