That's interesting.We'll Sony, Nikon, and the Canon's I tried all just can't focus on certain extremes. Such as a fence or even the ribs on a lens.this video shows the issue on a Sony, but it is not a Sony specific problem.
I guess speed and accuracy (when it works) are more noticeable in general than not being able to focus on certain patterns. Because I don't think many people would class M43 AF as better than Canon or Sony (although perfectly usable of course)
It is somewhat reassuring and exciting though, that if both these brands can deliver the amazing AF systems they have now while still having room for improvement in terms of the core technology used, we should see some sci-fi stuff in the next few years.