What I have learned from the Panasonic Lumix GM1 and GM5
My first Micro Four Thirds camera was the Lumix GM5. It was a great improvement from my 1/2.3 inch sensor bridge camera. I was very enthusiastic when I started using it, and I got some nice pictures with markedly better image quality than on my previous camera. However, a rather large number of pictures came out a bit blurry. The great thing with the GM5 is that it is very small and light and easy to bring everywhere, but also a competent camera with one more dial than the GM1. The bad thing is that it is very small and light which means there is no room for image stabilisation in the camera and it is too small for my hands. I had trouble holding the camera still. So I ordered Panasonic's grip that screws on the bottom plate. It helped a bit, but I still got blurry pictures too often.
After about a year, I bought a used Lumix GX8 which I still use today. It is large enough to be ergonomic and has good stabilisation. There was an issue with shutter shock which is why it was cheap on the used market, but a firmware update fixed the issue by using the electronic shutter when needed with certain lenses at shutter speeds where the mechanical shutter was problematic. Unfortunately, the issue affected the 14-140 f/3.5 - 5.6 lens the most and it was one of the lenses offered with the camera as a kit when it was new. I don't use that lens with the camera and I have applied the firmware update and switched on the automatic selection of electronic or mechanical shutter that takes care of the shutter shock problem. It's a great camera that even if many people say it is large, is still small enough with the right lens (the 20 mm f/1.7 pancake, the 14 mm f/2.5 pancake, the 12-32 f/3.5-5.6 zoom or the 14-42 f/3.5-5.6 Electronic Zoom) on to fit in my jacket pocket.
A while ago I could not resist to buy a used GM1 that came with both the 14 mm f/2.5 which I had sold some years earlier, but wanted again, and the 12-32 zoom. My thought was to sell it off again with the 12-32 and keep the 14 which I hoped would give me a very good price on that 14. Once I got the GM1, I felt it called out to me to try it a bit before selling it off. It was even lighter and smaller than the GM5, but it lacked any dial except the wheel on the back of the camera which made my usual M mode shooting from the GX8 very impractical. With it set to iA or P, it makes a lot of sense as an emergency camera that fits even smaller jacket pockets than the GX8 + 20 mm f/1.7. However, I soon discovered that for more than a few pictures, it is very uncomfortable to hold and I shake more than with my GX8 which leads to blurry pictures, especially with unstabalised lenses.
The GM5 and lately the GM1 has taught me once again how much I love my GX8. It is large enough to fit my hands, so I shake a lot less with it than with the smaller cameras. And it also supplies in body stabilisation which works with any prime and even Dual IS with any stabilised Panasonic Lumix or Leica lens. It is large enough to also have a great EVF which is another weak point on both of the small cameras. On the GM1 there isn't one and on the GM5 there is one that uses a technology that makes my eyes water. And with the larger size of the GX8, I also get room on the camera body for two well-placed dials, one around the shutter button and the other on the back for thumb use which makes it easy to shoot in A, S or M mode which I prefer. In addition, there is a third exposure compensation dial which I seldom use. The GX8 is small enough to be a daily carry camera in a jacket pocket with one of the smaller MFT lenses, but also competent enough to be the only camera I need. With the GX8, what holds my photography back is me, not my camera.