[Autofocus] I hesitated to upgrade from the E-M5 mark II mainly because of the negative comments related to the "plastic" build and toy like feel of the mark III. But as soon as I received mine, I was relieved. It might not feel as "premium" as the mark II but it is still very nice to hold and use.

What I like (compare to mark II):
The 20 MP sensor is less noisy and might have a bit more DR than the old 16 MP one.
Phase detection AF works great for video.
Speaking of video, the DCI 4K with flat profile produces nice files.
IBIS not as audible and might be a bit better.
Top plate controls similar to E-M1 mk III which makes it easier to switch from one camera to another.
And the biggest upgrade for me: OLED electronic viewfinder that can be used with polarized sunglasses!

I don't have any complaint so far but maybe it is because this is not my main camera. I bought it specifically for when I am hiking or biking and I don't plan on using it with heavy lenses, tripod or video accessories.

So for someone with similar use cases than me, I would highly recommend it. For a more general purpose camera, the E-M1 mk III or OM1 would make more sense. Or the Panasonic G9 if phase detection. AF is not a must.

[f/4] I bought the 12-100mm to have a relatively fast, high-quality super zoom for photographing trains and trolleys. I also have the excellent 14-150mm for times when size and weight are more of a consideration. I've used the 12-100mm on the Olympus E-M1 III, OM-1 and Lumix G9.

I seldom shoot wide-open but like being able to shoot at f4 in lower light situations. I don't shoot close-ups or selective focus, so the majority of my exposures are taken in the f/5.6 to f/8 range. I only shoot RAW files and all photos are edited in the current version of Photoshop before being posted or printed. The primary end-use of my photos is posting on Flickr or occasionally making 8.5x11 prints.

I don't have any primes to compare with the 12-100mm, but the lens has a beautiful optical quality that justifies its size and price. The lens handles very nicely on larger M43 cameras but might be a bit awkward to handle on smaller and lighter cameras.

[7.7 x 5 x 4.4"] I use it for all around photos. Very nice lens!

[f/4] Great focal length and sharp as any OM pro lens

[f/4] I recently purchased this lens as the price has gone down a bit since its first launch, so I decided to try this together with my OM System OM-5. I do have the Olympus 12-40 f/2.8 Pro lens so I was debating with myself if I should get this lens or not, as the reach is just a little more (90mm 35mm equivalent). Once the price dropped, I couldn't help myself from getting it! -I'm very happy I did though as the f/1.2 aperture gets that extra bit of light and has a much better Bokeh effect than the 12-40mm f/2.8 pro lens. Taking photos of my girls was easy even when moving around a lot and even stopped down to f/1.2 the eye focus is fast and sharp. at f/2 this lens is very sharp but f/1.2 its still plenty sharp. Another thing to be aware of is that it is almost exactly the same size as the 12-40mm f/2.8 OM System lens. So I have a storage case that you can easily have several lenses all the same size
and depth, another reason why I love the OM System (Olympus) lenses. The build quality is really impressive and the clutch focus ring feels good in the hand. Keep in mind this is much larger that the 45mm f/1.8. I tried both lenses in the Olympus store in Taipei (which is awesome) and the bokeh is truly at another level in this lens and the reason why I purchased it.

[f/22] You can take this lens anywhere and not need to carry another. Covers everything you'll need. This lens is a little heavier than the 12-60, but for me well worth it. Fun to use and easy. You'll enjoy taking this lens out and the sharpness is top quality.

[0.25x] Great camera, 2nd Olympus purchase and I have enjoyed the image quality and small package.

[7.7 x 5 x 4.4"] I enjoy this camera. I previously had the OM-D EM10 Mark I. This is a wonderful upgrade. Much more powerful, much better picture quality and autofocus etc. I was immediately able to use most its functions as it's pretty similat to the EM10.

[84° to 27°] This is an excellent lens. It’s slightly heavier than the basic kit lens (see my other review of the 14-150mm Zuiko lens). While it exhibits very good sharpness in the center, it’s a tad soft at f/4 in the corners. However, at f/5.6 and f/8.0, the lens becomes exceptionally sharp from center to corner. It’s a superb all-around zoom with an equivalent focal length of 28mm to 200mm in full-frame format. I highly recommend this lens for critical photography work (using one lens !).

[58 mm (Front)] I'm a recent convert from Canon full frame mirrorless. This 45mm lens creates bokeh similar to the RF 85mm 1.2 DS lens, but you aren't losing 1.3 stops of light gathering. The lens is definitely tack sharp, but has extremely smooth falloff. It's pleasantly tiny compared to fill frame equivalent lenses, and is also pleasantly less expensive. I'm very pleased with this lens!