I wish one of you A9 A72 owners were around in R.I.
My own experience is 2nd hand, and purely anecdotal, but I was just mentioning in another thread the following;
I came back from a trip to Newfoundland last week, and despite it being mostly vacation/landscape shooting, I had two opportunities to shoot alongside other photographers that ultimate test subject of AF ability, birds in flight.
Cape Bona Vista: where Puffins, truly small fast erratic flyers, were a constant opportunity with both pure blue sky as background, or busy landscape. VERY difficult BIF shooting here.
Cape St. Mary's: Gannets and Kittywakes offer both easy large (6' wingspan) and predictable flight paths in the Gannets, and the kittywakes are fast agile and small, a bit like a common tern. No busy background, in fact dense fog contributes to make this the easiest BIF shooting I have ever encountered.
In both locations there were a number of Sony shooters mixed in with the Canon and Nikons.
At Cape Bona Vista,. A Sony A7II equipped photographer approached me, due in large part to my fielding a 500mm for getting the scenic pose shots of the nesting Puffins. I am not sure of the focal length he had, but it was Sony, and approaching the size of the Canon 70-200/100-400. (do Sony make a 100-400mm for the A7 mount? if not I have to assume it was a 70-200mm)
He told me he was unable to get a single shot of the Puffins in flight. when I returned home I found that with 5D4/7D2 on the 500mm and 7D2 on the 100-400mm I was getting often 80-90% in focus.
At Cape St. Mary's it was a similar situation, but even better where the 7D2 was providing 10 FPS of in focus Gannet shots. Pretty much 100% if I did my part. Here there were 3 Sony shooters, one with a Sony lens, one with an adapted Nikon 70-200mm and one with the same lens I using, a Canon 100-400mm VII.
Again, the Sony shooters were all showing frustration getting the BIF shots, where I was in BIF heaven as nothing is so easy as to get a good BIF with the fog = ZERO back ground distraction. Literally the easiest BIF shooting I have ever encountered.
So is it the hardware, or is it it these fellows and women that can;t keep up with this old rusty out of practice photographer?