I recently sold my M6. Bought it to compare with my M4/3 equipment. I liked the M6 for the most part in terms of it functioning, pic quality capability and compact size. It could pass as compared to M4/3 as a competent compact camera. I had moved up from an M100 as I liked the potential and was considering going from M4/3 altogether.
But as stated here, the lens options were the problem. My M100 15-45 zoom was actually pretty good. Not so much for the M6 lens so I kept the one from the M100. I purchased a 55-200 and it was also Lacking having soft corners. I was very happy with my 22mm and pretty much kept it on the camera. Sharp, compact and I did not have any issues with hand holding.
Olympus produces some really nice lenses at a range of prices for both zooms and primes. The 12-40/4 zoom is fabulous. It really bothers me that a very capable company like Canon cannot produce a consistently good set of lenses. I never experienced QC issues with Oly lenses, although possible. I purchased a Nikon 10-20 zoom and it was clearly defective. The second Is great. No issues. Again from another very capable company. Do the two largest manufacturers have the greatest lens QC issues? If so Is it because of the volume or the manu process?
It is obvious from reading so many comments in this forum that people do want to experiment with different camera and lens options but it seems to be a struggle to stay optimistic when venturing beyond the basics. I am going back to the basics focussing on what I hope to be competent, trustworthy equipment that gets the job done, regardless of who makes it. The company that does that consistently gets my dollars.