I bought one because I thought that I would use it all the time. Unfortunately, I hardly ever use it. I found the angles of the shape a little weird, and so I ended up bending mine so that it would sit on the leather at a better angle to leave a better line. Even with that, it still hasn't found a regular spot on my workbench.
That looks cool! I haven't tried it, only seen it available on the usual chinese websites.