First, it does not sync terminal.
Then it 568EX II has a recycle time 5 to 6 seconds (with battery to max capacity and a 100% power) and has no outlet to an external battery (which would reduce retraining ). So, for intensive and genuine use, and if we do not want to wait 5 seconds between each trigger is grated !!
Finally, the construction is more "plastoc" than plastic. Basically the construction seems less convincing than the Canon 600EX or 580EXII ... This construction is also less convincing than his little brother who gets YN-565EX feature for feature that of Canon.
Its only advantage (not least) against the YN-565EX is its management of the HSS (High Speed Sync) which can prove useful in certain circumstances.
The YN-565EX takes the advantage, in my opinion, with its big buttons, more convenient than the central wheel (which can be found elsewhere on the 580EXII) ...
So, except for HSS, I generally prefer the YN-565EX.
