Zass’s are good but you pay a premium. I have only used a couple hand mills, I have two Cimbali Max commercial grinders and a Cimbali Jr on the espresso bar, but the Mazzer Robur is king, and cost as much as a small car. I had one on the espresso bar for a write-up, along with my Mazzer mini, Super Jolly, a couple of Macaps, purchased the Max.
We have a large hand mill following and thread on Home-Barista you may want to read over,
Hand (grinder) Jive-a photo essay.