The world of guided knife sharpeners is divided into clamp-based and working table-based. Either have strengths and weaknesses. Table-based sharpeners offer the even sharpening angle across whole blade. Clamp-based sharpeners offer the consistency in every point during whole sharpening process. Table-based are more universal, while clamp-based have shorter learning curve. Hapstone knife sharpener belongs to both worlds now with Rotating Clamp System upgrade.
Courtesy of Mr. Wizard. Please read chart explanation in README.