Electric shies specially when you have a mess of pan fish like perch, crappies etc
For bigger fish, I don't really care, I will use whatever is handy, quality of fillets will be the same either way for me.
I do it quick enough for me, I am not in a marathon or any competition, I have a life other than filleting fish, lol
Trick to keeping any knife sharp is try not to use it on scales and bones, I slab my fillets with a cheap serrated knife, and do the final skinning and trimming with a razor sharp fillet knife,
Sharpening a knife AND knowing what is "sharp" is a whole different subject ?