I can't say a thing about cast nets... Never tried them... BUT... knifes on the other hand... I've tried probably 2-3 dozen over my lifetime, Cuda's, Rapala's etc. For me, the absolute best fillet knives I've used and continue to use are my 2 Dexter-Russel 9"ers. Easy to sharpen, easy to clean, Special hi-carbon stainless holds an edge and doesn't stain. And the nice sheath is a plus. (White is easy to find in the dark) Look at this link. http://www.dexter1818.com/shop/sani-...sh-fillet.html
At the bottom of the page on the left is the 9" carded knife and sheath. Of course not everyone will like or want a 9" knife but for me doing Salmon fillets, it's the only way to fly. Fortunately they also make smaller blades, (The 8" carded set will suit most everyone) all with the same steel and handle. My knives are well over 30 years old and still going strong. (I got mine in 1986) Hard to beat that kind of ruggedness. I'm betting that if you buy them you'll treasure them just like I treasure mine.

TWO HUNDRED BUCKS FOR A CAST NET?!?!? not sure if you guys are aware of this but the county I live in, Nassau county is THE SECOND HIGHEST TAXED COUNTY IN THE ENTIRE COUNTRY. sometimes I look around and see what people from other states have and realize...... I make decent money and I aint got sh1t!!!!! TWO BEANS ON A CASTNET??!!?!?! I spent 38 bucks on a 6 footer and feel like I got raped. I plan on eventually getting one of these electric knife sharpers and putting sick edge on all my gear. ok, so what knife sharpener you guys use???

Read charlie,read. I paid $50, before that it was Betts, but with the price of lead, they've gotten pricey too. The more expensive, the heavier and easier to throw.

Also a fan of dexter russell

I use a lansky sharpener, oil stone, and 800-1200 grit sand paper on a piece of glass

Go get a Percy cast net. He's out on Staten Island and he won't let you leave with it until you can throw it. They're like $300 now but you'll know how to use it. Too rich for my blood though. I'll just continue to try and teach myself.

I have always found that the sharpness of the knife is much more important than the style or brand.

Learn how to sharpen well and you filleting will improve.

My favorite fillet knife right now is a blue handled Rapala I got for $5 in a clearance bin.
My second favorite is one I got at K-Mart 40 years ago, was probably a buck back then.