Less finger-to-blade contact when changing (since you don't have to screw anything back down) and you can clean (by loosening the head and running under water) without taking the blade out.
+1. Plus no parts to drop on the floor.
Less finger-to-blade contact when changing (since you don't have to screw anything back down) and you can clean (by loosening the head and running under water) without taking the blade out.