When is a collet considered the best way to hold a tool bit? - as opposed to a jacobs chuck or a keyless type of device.
On Dremel type rotary tools, I prefer to replace the collet with a chuck. I wonder if there is a way to make this replacement on roto-zip type tools.
I'd be happier if rotary tools used a bit holding arrangement like modern impact drivers. That would require that bits be made with a hexagonal base.
The advantage I see with a collet is that it can soften the shock on the tool by slipping if the bit sticks.