The risk with an electric sharpener is wearing out a blade prematurely. If you're using a steel the set the edge on a blade, it just takes a few licks and setting a new edge by grinding should only need to be done annually. The other thing is with frequent grinding the cutting edge will become too wide and the blade won't cut as well and then you'll need someone who knows his way around a belt grinder to put a new cutting edge on the knife.
