Just got back from the Eastern Conference, and Toshio Odate discussed roller jigs during his sharpening presentation. He thought they gave you TOO sharp of an edge - it will be too fragile, and chip off (at a very tiny scale) thus dulling your chisel. He felt that using your hands without a jig gives you a slightly imperfect edge, which actually lasts longer. We watched him do this with a planer blade, and then he planed some pine for us. The shavings were so thin, you could read fine print through them! CB.