I got a Nova this year for ducks...dont let nobody kid ya, 3.5" knocks the crap out of ducks. I'm using some cheapo Winchester Xpert #3's that I got on sale with the factory modified choke tube. Ive lost a couple ducks that dove on me, I dont have a dog, but, generally they are dead or dying when they hit the water. Not really longer shot, better pattern. Get the 3.5" for waterfowl...you'll be glad ya did.
"You get what you put in, and people get what they deserve" Hank Jr. and Kid Rock