The little side-clamp honing guide is my favorite bit of sharpening equipment. But it frequently is criticized for two shortcomings:
• It is poorly made and sloppily painted. So you have to tune the little sucker up before it will perform reliably, especially with chisels. This is a 100-percent valid critique of this honing guide.
• You cannot rely on the honing guide’s directions for setting the correct angle on a plane iron – i.e. make the iron project 1-1/2″ to sharpen a 30° angle. This inaccuracy is because these instructions are based on using thin irons only, back when most plane irons were consistently about .08″ thick. Today many manufacturers use thicker irons.