same, or at least they're washed carefully and individually. my concern with the electric machines is that if you dwell in one place - you just made a nice scallop in your blade. same thing with the draw-through devices if you can't take a full stroke consistently, such as if the bolster blocks full insertion of the blade (one reason I like choils). you end up grinding a step into the edge. obviously I'm talking about this sort of gadget, not something only an enthusiast would have like a Tormek. honestly, the vertical method is so safe and aligned with normal use of the knife that anyone should feel confident having a go, and as long as you keep the knife aligned roughly the same way each time you'll get a better result than you started with.