I had the original EOS-M back in 2013, but got rid of it after only 9 months (along with my 7D and EF-S lenses) when I decided to give M4/3 a try. Since I had got an awesome deal on the M, and most of my lenses had been bought used, I didn't loose too much on the sale. I did end up losing a LOT more when I bailed out of M4/3 18 months later
At least I was smart enough to hang onto my 6D and EF lenses. 
I now have a G5X, and G3X for compact carry always or travel but just really missed the M. The G3X and G5X are nice, but looking back at the shots I took with the M, they just don't compare.
So, after serious thought and hours of interwebbing, I decided to sell my G3X to fund getting the M3. I really don't need the zoom range of the G3X for travel and in those instances when I do need a longer lens with the M3, I can put my EF-S 55-250mm STM on and have a 400mm equiv so it gets me really close.
The M3, EF-M 18-55mm, and EF/EF-M adapter arrived today. Mix and match new body, white box lens, and 2nd party adapter for a total of $575 and I am very excited to have an "M" again.
Now looking for a good deal on the 22mm and 11-22mm lenses to complete the kit.
Hoping to get out this weekend and take some shots and start adding to this thread.