I could also have asked: is, for instance, a super jolly better than a mini regarding grind quality?
Well, I expect the answer to be yes, but why?

From what I know, here are some common features and differences:
*Looking at them from the outside, I guess their respective burrs are mounted in the same way.
*The burrs are different in diameter but they spin at the same speed on both models.
*The SJ is more powerful (which sounds logical since it has to drive larger burrs).

If the burrs have the same shape, I don't see what could make a SJ better than a mini. If it really is, I'd like to understand why? Engine torque?

Larger burrs, spinning at the same speed, have a far larger square footage in play grinding beans than smaller ones, and therefore will grind more beans faster without imparting any more heat generated by faster spinning, smaller burrs keeping pace by turning faster.

If you have milliseconds to spare in your day, maybe not a giant difference. If you have customers waiting, time is money.

A bean gets ground travelling from the inside of the the burr to the outside, with most of the grinding happening in the area where the burrs are closely spaced. The large the burr, the longer this path, and the more gentle the grinding action.

There are some exceptions to this. The Baratza Vario has a very short grind path, but still produces very good grind quality. Still no clue why.

another_jim wrote: The large the burr, the longer this path, and the more gentle the grinding action.

I might be misunderstanding what it is that you're saying, Jim, but it sounds like a (just for the sake of easy math) burrset that has a three inch outside diameter and a two and a half inch inside diameter and a burrset with a one and a half inch OD and a one inch ID have the same length grind path, ergo similar grind capabilities?

There has to be something more, neh?

The lower this linear speed, the better the grind, right? Or it's not as easy as it seems?
Same rotationnal speed with larger burrs means a higher linear speed at the edge of the burr. From this point of view, a mini for instance should perform better than a SJ regarding quality (not throughput). Right?