The units come neatly packed and are easily accessible. The only negative at this stage is the limited scope of the instructions provided with the units - a single sheet with diagrams showing how to pair the units but nothing more. Having said that, the units are fairly self explanatory for anybody beyond absolute beginner so you shouldn't have too many problems.
The flash light is bright and the recycle rate is more than acceptable for the vast majority of situations. The Air1 wireless unit pairs with the main flash easily and, having used this now up to 100 feet away, haven't had a single misfire yet.
All in all, I'm impressed with this general purpose piece of kit and can highly recommend it to anyone looking for a reliable flash and remote without wanting to break the bank.
I found the setting up of RC linkage between the gun and the Air Command unit a bit confusing but, once done, the system works very well.
I had been using a similar system for macro in the Olympus m4/3 system, with their R series flash guns. I wanted something comparable for my Sony A7R. I had to wait a few weeks for the Sony Model to be available (not labelled as such, although the hot shoe contacts define it!).
I use TTL mode, usually in camera manual mode. I have been very pleased with the results I was surprised how well the drop-down diffuser works.
There is a general issue with various flash guns that the diode lights e.g for charged or switched on are difficult to see in bright light. The Nissin ones are particularly dim but, once they have been seen, the session can continue without further reference to them.
I am not in the position to state it as a fact but my impression is that they give plenty of flashes out of a set of batteries (I use rechargeable ones). Neither can I comment on output being reliable, as I don't use manual flash.
I use mostly off-camera flash and the detachable shoe which is provided is of a type I would not be without.