I love the look and feel of these mills, but tbh it is style over substance. I am a big fan of ‘JJ’ but have pondered on whether to send back. 
The gradient on the grinder is pretty non existent, hard to tell the difference, and the first salt I used which was rock salt was such a fine powder it clogged around the top and when you picked up the mill salt would go everywhere. I change to sea salt and it was a little better, but after a couple of days of use the grinder just dumps out salt dust in one hit.
I have lots of ‘JJ’ products that I love, but not this one.