After using both the i40 and the Di700A with Air 1, I think I'm going to stay with the Di700A. The i40 is a really nice little flash, but it is almost too small. While it balances really nicely on the A7R II, it won't hold any of my flash modifiers other than the included diffuser. Although the Di700A is larger, it gladly holds my Flash Benders either on or off camera. I may pick up another Di700A and possibly a i60 later to stay in the Air 1 system.