Took my M6 + EF-M 55-200mm to the Queen + Adam Lambert concert. First concert for the M6.
As with the M3 previously, no problem thru security or the metal detectors; the body looks like a ordinary point-and-shoot, and the plastic lens passes thru with no issues. This is one of the reasons why I like having the M-series... I used to use long-zoom point-and-shoots like the Sony HX50V (which gives you 720mm!), but I like having RAW and the better quality from the M.
Seat on the 2nd level, so not close. The 55mm was not wide enough, but the 200mm served me well. A lot of the photos are cropped for more reach.
I would have preferred the range of the Tamron 18-200, but that one is a little larger and definitely less plastic, so I bring the 55-200 instead.
Battery life: Took 620 photos. The battery did not even drop a notch. I had image review set to off, and the display brightness at minimum (it would have been too bright otherwise anyway). Didn't bring the EVF. Eco mode off, display off after 15 sec.
I really appreciate the physical exposure compensation button at concerts, due to challenging lighting conditions. I used AV mode with exposure usually set between 0 and -2.
Focus in general not a problem, except for the few really dark or bright cases where it struggled a bit. But overall did well, and better than the M3.
One annoyance: I had set ISO to 3200, but once in a while I would find the ISO had dropped to 2500 or 2000, likely as a result of the button activating and turning as I used the camera.
With that here are some of the photos...
A 55mm trial shot before the concert

Brian May (that's Dr Brian May) and Roger Taylor, the two original members of the band


Another 55mm shot
Doing a stereo 360 degree "selfie" with the audience
Adam Lambert is pretty good, but probably not the same vocal range as Freddie Mercury

Oooh, shiny disco ball!


And finally, an iPhone photo to capture the wide view from my seat. The 55-200 + ability to crop is definitely handy:
Pre-concert iPhone snap
Ali