I received the 1Z Q Air today so here are some comments:
The steel inside mechanisms are very attractive to fine particles due to statics, and the manual says it cannot be washed. So I had to use a rocket blower to clean it up afterwards, but given the trouble I probably won't cleaning it a lot -- maybe once a week. Next time I will try to spray some water on the coffee beans to reduce static. https://imgur.com/wkk5fAA
The upper chamber hold exactly 15g of my coffee beans -- these are ordinary sized beans around 1cm wide. So maybe I'll use the scale less if I wanted to cook exactly one serving. But I can foresee this become a bit tedious if more servings for 2-3 people are needed. The lower chamber is about 2/3 full after grinding the 15 grams of coffee.
It is very compact compared to my old grinder. Construction of the unit is solid. Cranking the handle is very smooth. The (online) manual is very detailed on instructions of how to adjust the granularity. The adjust button is stepped and has dials on the side so one can be very informed about current settings. https://imgur.com/6I68kAq