tks i will look at this flash but
what you mean by 100% compatible
what will the canon do that the Di622 dont do
Compatibilty, in general, may become an issue because most aftermarket products are reverse-engineered to work with a production camera available at the time the aftermarket product was developed. The better-known recent examples of compatability problems have been with third-party lenses. A product produced by the camera company, itself, will generally be compatible with its range of cameras, and if not, the company's website is likely to say so.
For a specific example that I have experienced, my Nissin Di866 II, when used on a Canon 5D, resulted in significantly warmer images than a Canon 580EX II on a Canon 7D, when I was using both cameras in an artificially-lighted parking lot with mixed types of lighting. (Both cameras wee set on AWB, which is my usual practice when shooting in a hurry.) I removed the Nissin from the 5D, and then used the 580EX II on both cameras, which solved the too-warm problem. To be clear, this example involved extraneous mixed lighting, a variable not easily duplicated.
Later, at home, when I shot an image or two with the Nissin on the 5D, using AWB, the images had good color balance. Therefore, my Nissin flashgun will usually perform well, but that particular circumstance, with mixed extraneous lighting, caused a problem. At the time, the quickest solution was to simply use the Canon flashgun on both cameras.