Are electric knife sharpeners any good?

[TastyReuben]

I can tell you to also be careful of professional knife sharpeners - I’ve had that exact issue of some overzealous one using an electric sharpener and removing too much metal, leaving a dip at the back, making that part of the knife useless.

 

[GadgetGuy]

I have one like this. It seems to do the job pretty well. It also sharpens scissors & screwdrivers as well.