Danish photographer Thorsten Overgaard has a very comprehensive review on the Leica Q (from May 2015). A camera not without quirks though:
I must say the Auto Focus caused me a few problems at f/1.7 in that I some times unknowingly had been focusing at the background between two main subjects in the foreground that I thought I had nailed the focus on. As time has gone by, I have gotten the hang of it. I think.
Then Overgaard goes on explaining how to use various features of the camera properly. Read thoroughly if you have a Leica Q, or are simply curious.