I believe they are supposed to be used with a mag chuck (just being a smartass)
I have a big and small mills, so have a want that is maybe not the same as everyone's. I'm going to use a small mill for small work, so I would like to a jaw height on 2" vise say 1/3 of that of a 6" vise. But with a grinding vise I get a jaw for a 2" vise that is likely the height as the 6" Kurt.
the Happy Vise arrived yesterday. I'm getting to old for happy vices, but you can have a happy vise for $100.
I think its going to be too high a profile for the little BCA mill, the angle lock mechanism eats up a lot of day light. On that attribute, the grinding vise is probably better. I still attached to the idea of making a low profile angle lock vise
I'l try to survey the Happy Vice this weekend and report back, but its a busy shop weekend as it is