The handle that came with my new vise was, well let's just say "so not good".
I had seen the post by Rossbotics where he made a Rota Broach so he could make a very nice milling vise handle.
Here is the link: Rotary Broaching Tool
I made mine a bit larger since I wanted a "Speed Handle". Man is this thing fast. One flip and it runs 10 turns of the lead screw.
After 4 flips (kinda like starting a glow engine) the vise has traversed the entire throat. Of course first I had to make the tool and the
broach for cutting the Hexagonal hole thru the center. Then it was just a matter of some lathe work and a bit of drilling.
Here is the result: