Hi Phil
I’ve read quite a few reviews of Nissin and another make Yongnuo. Not sure if you can get the latter for Canon, being a Nikonian myself 
They got pretty good reviews in a magazine I bought for the article on off camera flash.
I think I will be buying two Yongnuo flashes with the i-shoot wireless flash triggers. The Yongnuo 560 also has optical slave mode.
Don’t know if that helps.
Stu