I am really loving this amazing little camera! Its small size and deceptively simple exterior appearance doesn't begin to reveal the level of sophistication that is available here. Of course I am greatly appreciating the extra reach of the lens, and I also like the new features such as the touch screen/touch pad. This is used for establishing the focus point, and can be done either using the camera's LCD screen (touch screen function) or the EVF (name changes to touch pad as the LCD screen is dark but one can use a finger on it and see where to aim while looking through the EVF).
The menu system, as always, is a bit daunting at first and I spent some time doing the initial settings, then tweaking here-and-there, then tweaking further. When I got to a point where I was ready to try out the "My Menu" feature, I tackled that and it's another nifty new tool! Now I can quickly access that and immediately click on the "format" function and format a memory card without needing to dig through the entire menu to find "format" or some of the other functions I use frequently. This is similar to, but a bit different from setting custom buttons for specific functions.
Gary Friedman is working on an eBook about the M6, and Alexander White is preparing a print book for publication as well. In the meantime I found an excellent setup guide (free!) by Wim Arys:
https://www.wimarys.com/rx100vi-setup-guide-with-tips-and-tricks/ It takes the user step-by-step through each of the menu items and clarifies them (sometimes Sony's language is a bit obtuse). This was very helpful for me and I'm sure it is to others as well.
The lens on the M6 is sharp, sharp, sharp and autofocus is quite fast, more so than on earlier iterations of the RX100 series. Some people were not pleased at hearing that the lens at its widest point is f/2.8 as opposed to the RX100 M5's f/1.8, but Sony has an answer for them: the new RX100 M5 A.....a revised version of the M5 which includes some of the improved functionality and features of the M6 (but not all), while retaining that valuable f/1.8 - f/2.8 lens and its 24-70 range. This will be released in early August.
I haven't tried eye focus, since I don't really shoot that many people, and I haven't yet tried shooting birds-in-flight (BIF), but am really enjoying exploring with my new little camera: