I think drown and I are currently on similar wave lengths. Regarding his points:
1. My atom was pretty fluffly, but the niche has been the same, almost the same as my Kinu M47
2. Its not much, but yeah, the niche is louder. Part of it is, you can look in and see the burrs. Theres no column of beans or a machine top between you, its just a piece of plastic. The atom also purred, where the niche chews.
3. Theres low retention measured in full grams (atom), and then theres the niche. It feels as low as my hand grinder
4. I didnt even bother buying the blow up. Even if it did work, the idea of finishing a grind by exercising some bellows, forget it
5. What drown said.
The fit and finish of the Atom was way more serious, and felt more 'pro', however, the niche fits my lifestyle way more, and as admittedly 'cuter'. I hope that niche can create a legacy as long as Eurekas.