I've been shooting both BOSS #5's and #4's in the magnum's out of my 12 guage in 3". I used them each for one full season and found better success with the #5's so that's what I'm going to shoot until something better comes along. They're spendy but not horrible, for the amount of money I spend on pheasants it's a drop in the bucket. Seems to hit plenty hard, had a few cripples, but also folded plenty of birds out past 40 as well.
I only shoot non-toxic, my uncle was a 40-year USFWS waterfowl biologist, the problem isn't necessarily lead in the water or even hitting the bird with lead for that matter, it's if they grab some lead and it ends up in their crop. A duck hit with lead shot won't die from lead poisoning (other than if you kill them obviously), but if they go to the bottom of a pond and grab a BB and it ends up in their crop that's where the problem lies. Everyone here has seen a public duck pond on opening day, imagine the amount of load that ends up in the water, it's a lot.
I understand the argument for people wanting to use lead on uplands, with me hunting a lot of WPA's I just shoot non-toxic all the time so I don't have to mess with it. It probably doesn't matter, but if I shoot one over water I don't want my load killing some duck a year later so I'm fine shooting the more expensive shells, but I'm not going to tell someone else they need to do the same either.