The build quality of the two flashes is truly amazing well and I do not exaggerate when I say that the case is more workable, as for example with a Canon 430EX, I own also.
The surface texture is slightly rough and I could not find anywhere sharp ridges or improper fittings. Everything is stuck, nothing creaks or gives in to pressure.
About how I can also only positive things to say: the two flashes are working exactly as I also expect it of them.
Mostly I use the two devices "unleashed" ie, remotely controlled by a RF603 C that I use on my Olympus OM-D.
For this I had, however, only the transmitter a little to rewire (two contacts in RF 603 C, you must combine - there are also instructions on the net). This of course has nothing to do with the two I purchased Yongnuos 560 III.
If you have the channel set correctly, both devices just work perfectly together with the RF 603 - I'm really excited.
The power can of course as with the other 560ern manually from 1/1 to 1/128 rules including fine adjustment in 1/3 increments.
In addition, it is possible to make by "Multi" a strobe setting.
Moreover, does the 560 III as a normal Slave (SL 1 and 2), ie triggered by a built-in camera flash or a plugged.
All in all I would recommend the new "Mark III" across the board.
The only complaint I could possibly be the display that just in the dark and the lights has a very limited viewing angle.
Nevertheless - a really hammermäßig great device :)