I've got three elec fillet knives (110V) ... if that tells you anything ... LOL !!
Seriously though ... once I realized that I didn't have to scrape the scales off, behead & de-gut a fish before it was ready to cook, then (once cooked) pick thru the fish to avoid getting a bone in the throat ... it was a no brainer to have & learn how to use an elec knife. All of what I cut off a fish, with an elec knife, is eaten .... which is equivilant to what I'd have picked around the bones & eaten, if the fish hadn't been filleted. So, by my way of reckoning, I clean them faster & easier, yet still end up eating an equal percentage of the available meat.
Now, that's not to say that I don't/won't clean some the "old fashioned" way, especially Crappie. And especially if I'm going to eat them shortly after catching them. The skin does add a little sweet/nutty flavor to the fish. Now, for stored catches (frozen & eaten weeks or months later) I'm most likely to filet them ... especially since the friends/family members that I give most of them to, want them that way.
I don't run the knife in a straight line, down the side of the fish, either .... it's more of a elongated S cut, starting on top of the head (above the eyes) & coming down around the gill plates, then towards the belly ribs. That way, I figure I'm gaining the meat above the eyes/gills ... to offset the sacrificing of the meat around the belly ribs. My fillets come out as one long single piece of meat, not a "check mark" shaped piece, but I still think I'm getting a equal or greater percentage of the back meat & overall % ... with little waste/loss. But, that's just the way I do it, and it's not intended to be a portrayal of "how it's supposed to be done". To each, his/her own, on the "how to" !!
... cp