I don't have one but I've used one.
If you're using it for triangulation tubes (where I think it had the most advantage over your eyeball and a sharpie), you still end up having to cut a tube that's shorter than the real piece so you can get the angle right for the contour gauge.
You can buy a lot of plain old tape, pencil, and paper for what those things cost and produce the same result.
Now, what that guy's doing in that picture is probably a different story!
Fighting never proves anything- except who's better.
'85 Toyota Rock Buggy- 37" MT/R's, Dual T-cases, 30 spline Longfields, a few other mods...
'04 Tacoma Dcab- Close to stock
'01 XR250R- Legalized