I've got an Oly M4/3. EM-5. It's great for some things (smaller package, stabilization, focus speed). Not good for others (too much depth of field, small sensor, 2x crop factor). This is actually two questions in one; Mirrorless and M4/3.
I love my Oly as a 2nd system. I went through the mental process of whether to ditch my Canon gear and my answer was resoundingly no. M4/3 doesn't deliver much of what I need, but it's a cool travel cam for when I want to pack light.
I still think about going mirrorless, but if I do, the front runner right now is Fuji

Last edited by ChrisF; 07/07/20.