New camera that's complex with new features, different from what he's accustomed to.... some features which probably should be avoided for certain situations... No surprise to me that he struggled with the AF a bit initially.
When I moved from 50D to 7D, initially my "keeper" rate when way, way down, too. My mistake was trying to rely upon the automation of the camera, and not taking control of the AF the way I'd done before. There were few other people using the 7D at the time, and none of the books or tutorials were out yet, so I was on my own figuring it out. When I finally sorted it out, learned to use that new-at-the-time AF system, my keeper rate went way, way back up... better than I'd enjoyed with 50D and earlier models. I would expect 7DII to be the same... on steroids since it has even more modes and tweaks and AF points to deal with! Temptation is to fall back on the fancy automation and gee whiz features... but I find Keep It Simple, Stupid still applies most of the time!
I'm deliberately waiting to replace my pair of 7D's with a pair of 7DII's. Let someone else sort out the issues, this time!