Ok, I got the Edge Weight Tool to work. I needed to subdivide the whole mesh, then select edges, then fire up EWTool AND click on the mesh item when I had the tool dialed at 100%.
But look at how the cube looks like in edit mode now (renders fine tho). The black "ghosting" is constrained tightly into each corner of the cube. Is that odd?
BTW, how does one zero the creasing when the EWTool has been dropped once?
BTW2, Modo's creasing is the best I've seen as you are not restricted to on/off only, instead you can have different levels of creasing. Superb!