Have him equal weekends extensively testing can, Works in ETTL and in manual mode Perfectly, had before the first start the firmware update be currently playing 1.8.1. went without any problems and takes about 10min.
Use win. 8.1 have the firmware update software therefore in compatibility mode (Win7) carried out and of course as an admin.
Have the flash used at an anniversary on Saturday, he also passed the same humidity test, as it has easily been raining all day.
But the evening about 200 photos shot at an event, Focus Assist is a bit unusual compared to my Canon flash provides good results. Lightning Solved always and Exposed always right.
For the price an absolute buy recommendation.
If there will be something negative to report I will add my review.