Well, it definitely was inferior to the 1D X I have. The silent shutter was nice, but I'm probably going to take my 300 f/2.8 next time and shoot with the 1D X.
i tried some tennis with it yesterday 5D3, seems like a LOT of misses at tennis (which seemed like it should be remarkably easier for the AF system, than soccer or football)
some might have been heat haze though, brutal heat and shooting from in stands (very close though) so that meant a different surface between me and the court, and some was definitely just me, but something seemed a little weird, kept wanting to jump back 2-4' behind a player at times (and focus on nothing, stuff behind player was more than 2-4' back) and even when they were just walking towards stands, at times it didn't seem to keep f/2.8 DOF dead on player, need to look into it more to see what the story it, i'm sure i probbaly didn't have the ideal settings and in other cases it was def stuff I didn wrong, but
I've had amazing one shot mode success with 5D3 so far (easily most accurate and precise of the bodies I've ever used for that) and it's done better than 7D under same conditions (I actually find 7D does worse than 5D2 for AI Servo more often than it does better for soccer). Oddly, not sure it's done better for AI Servo than my 5D2 yet. But I haven't really figured the system all out yet or shot more than a very little so it's hard to say. And some of the errors were my own.