Also, that is with the native Sony lens - performance with f2.8lenses (which will be from other marques and need an adapter) is something else again.
That is an f/2.8 lens, right?
I wouldn't judge a sony on its ability to focus lenses from other marques any more than I'd bemoan the responsiveness of third party speedlight systems on my canons. If adapters allow it to focus third party lenses well, that's bonus.
I'm not feeling moved to sell my 1Dx by any means, but it gives me new hope for mirrorless focusing systems.