Canon m5 is a great little camera, but it is held back by the following:
1. No cross type af sensors
That's for DSLRs that aren't using the DPAF for AF alignment/accuracy.
2. No selective af patterns like the 7d2
That's because it's not a DSLR... like the 7D II.
3. Poor af in low light
It has exceptional AF in low light. Better than all of the previous models. Faster too. Unless you point it at a blank wall or a blue sky.
4. No effective spot af
That's why it has a touch screen with a movable AF reticule. The DPAF sensor was actually patented for use on the EOS-M series cameras.
5. For flash photography, it does not use canon's pre-flash from their flashes and ettl is thus slow.
So the built-in flash is not exposure/color accurate but the external flash is too slow (but is exposure/color accurate)?
6. Lack of L type lens for the M series. Maybe competitors will get into the game
The reason it has an available EF-M-to-EF lens adapter is to give it full access to Canon's entire range of EF L-series lenses.
7. Tracking bif and sports is poor
Only with a long EF telephoto lens (eg 400mm) when the subject is approaching the camera head-on.
8. Most importantly, canon has not decided where to put their low end resources (rebel or mirrorless.) One will win and the other will disappear. Make up your mind Canon. Right now both are suffering strategic investment and time to market for improvements which means competitors (mostly Sony) could take future market share away===take future profit away.
Sony formally announced that the reason they recently faced bankruptcy and that it was exclusively due to their heavy investment into "mirrorless cameras". I think Canon should be expected to tread somewhat cautiously.
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I don't own the M5 but I've used one. And I own the M6 which is quit similar, if not identical in most ways.