Long response incoming (TLDR: I love them):

I have had 3 versions (2x of the 28mm and one of the 40mm) so far over the last 3 years, and I have enjoyed all of them. I first bought the base (black) GRiii 28mm, and I liked it so much that I bought the base GRiii X 40mm, for about 6 months I had both cameras at the same time, I mistakenly assumed I would continue to use the GRiii X 40mm more and sold my base GRiii 28mm. A few months later I reversed this decision by selling the GRiii X 40mm version and bought a new GRiii 28mm Street Edition (grayish blue body with copper accent ring, no performance differences). I have had the GRiii28mmSE now for about 1.5 years and zero problems or complaints.

You can read however why I didn't get along well with the 40mm version in this link:

https://medium.com/@foxfotoco/opinion-the-problem-with-40mm-4bcd89d5b640

I will note, my issue with the 40mm version is a personal preference thing, not a real complaint about the performance or value of the camera.

If I check my photos and looked at my favorites/keepers then the GRIII actually passes all of my other cameras easily. This is partially due to the fact that I carry it with me always and it's EASY to carry with me always. It's also due to a very practical lens focal length, being sharp at wide open f2.8, and the often overlooked macro modes + sensor stabilization, and built in ND filter)

The mixed reviews you'll see are either from people who want perfection unreasonably or don't take care of their stuff.

The GRiii does lack weather sealing but I've taken all of mine in the city rain many times and I lived in the dusty desert for much of their lives too. I simply bought a basic magnetic cap and have had zero dust issues (the most common complaint). Another complaint is that the battery life isn't amazing, but I have gone weeks without charging mine and I still shoot mine regularly. I do have a backup aftermarket Olympus battery (with more charge capacity by abut 50%) but rarely need it.

I would like to see a "GR4" include a tilt screen for easier landscape or low profile shooting. The lens is pretty perfect already, and I don't really want more megapixels in an APSC sensor so no need of improvement there.

I guess the only thing I'd really like to see would be something that fundamentally wouldn't be a Ricoh GR camera anymore. That would be some sort of interchangeable lens option, or a slightly larger body with an EVF for focal lengths like 21mm, 50mm or 85mm. But at that point im starting to describe a mirrorless version of the Pentax K3 cameras, or a Ricoh version of a Fuji body.

So for its intended purpose, the GRiii checks all of its boxes. If you want more from it, you don't want *it*.

Many times if I need more than my Ricoh, I just take my Canon/Leica digital body too, or a film camera. And then the Ricoh acts like a "pistol" to my "rifle" main camera.

Hope that answers things.