Vorneweg: In comparison shots (EOS 5D III, EOS 1DX, YN-586 EX II, Canon 580 EX II), no difference was observed even with ETTL. A "false Exposure" did not occur here (see the 1-star ratings), differences between the Canon flash and the Yongnuo were at best minimal. Even when adjusting Integral vs. More box in the ETTL metering occurred no major difference. I do not know what that went wrong, the rumored on the Internet series error occurred definitely when my measurements not (thankfully).
The level of equipment, the Yongnuo must not hide behind the Canon original. What safe for my second planned use (mobile soft box, radio) is still a very good feature is the audio signal when it reaches the full charge that you fortunately can also turn off. With my beloved Yongnuo YN-622C, the flash fires (of course) also perfect.
For less positive: The service is already the Canon a bit strange, because Yongnuo has again upped the ante a, already turning ("Permanent Press" instead switch) ... Is just the way you take left as long as the thing works. What I definitely do not like about the lightning - and also makes me a bit nervous - is a loud clicking sound from the flash head when triggered. Hopefully this is not a bad electrical sign, I will report here after. The overall feel compared to the Canon has slipped down a bit. Doing so "from the pack out" the plastic case was already a rather ominous scrunch of itself. The Flash "smelling" something bad electric (or plastic).
As already said, the small weaknesses at the feel you like to forgive, when the flash fires. He does this with me on both cameras perfectly with ETTL and thus he has certainly earned the four stars.
