I just wanted to share that I find the Nissin i40 a great flash option for the A7 series bodies. I first was suspicios because I like original brand units but in regards of small size, easy to acces flash exp compensation, tilt/swivel/zoom head this flash -IMO-just fits the A7 better than the bigger flashes. It even has a built in video light.
So far I can not find anything wrong with this unit-in the oppposite.
It is also so small that it is easy to bring with you.
I have no connection to the brand I just share my positive impression here.