I suspect free-hand on stones will always work better for me for the simple reason I don't have two of any knife and don't have to sharpen all that much. The stones work fine for everything, including a lot of woodworking tools -- now that I have them all flat and have learned what I'm doing, all those hand tools work great.
Anyway, if you are running production or semi-production and sharpening the same shape of knife again and again, any power system with jigs will reduce the time dramatically. Gillette automated razor blade honing in the 1920's for this reason -- vastly more uniform and far less hand labor, which is very expensive.
As far as actual edge results, it aways depends on the tools and the operator. I don't see a dramatic advantage to paper wheels, etc over high skilled use of stones, but if you can't hold a bevel angle steady the paper wheel and a jig will give you much better edges.
Anyway, if you are running production or semi-production and sharpening the same shape of knife again and again, any power system with jigs will reduce the time dramatically. Gillette automated razor blade honing in the 1920's for this reason -- vastly more uniform and far less hand labor, which is very expensive.
As far as actual edge results, it aways depends on the tools and the operator. I don't see a dramatic advantage to paper wheels, etc over high skilled use of stones, but if you can't hold a bevel angle steady the paper wheel and a jig will give you much better edges.