I just bought a 3.5" 12 gauge, a used Mossberg 535. I doubt very seriously it's going to pattern as good as the 90+ percent patterns I get with steel T shot out of my H&R 10 gauge single shot on a 30" circle at 40 yards. There's no place for a snow to hide in that pattern, either.
I AM going to see how that 12 patterns, soon as I get in the position to. The Mossberg is light, should kick like all billy hell. The H&R is 9 lbs, shoots about the same payload, and doesn't bother me at all. I shot 21 rounds one goose hunt and felt it, no worse really than 3" in my Mossy 500.
There is really not much difference in 12 gauge 3.5" and 10 gauge 3.5". 12 holds 82 T shot and the 10 holds 85 IIRC. But, that 10 sure does pattern sweet. I would think about getting a BPS 10, but I can't justify it no more often than I book a goose hunt. I didn't even hunt 'em last season, hope to book a hunt or two this year up around Eagle Lake, Texas.
I picked up a guide's AYA (I think) 10 gauge double once. The thing musta weighed 12 or 13 lbs. It was kinda shocking. I'm not sure how a gun like that could have much recoil. My buddy's BPS 10 is sweet. If I upgrade my 10 to a multi shot repeater, I'll go BPS. But, I am almost good enough at reloading, now, to shoot a double with the H&R. I managed to finish a cripple with it with a second shot. I'm getting better.
I like the single shot, really, gives it's own challenge and, heck, I shot as many as my bud last couple times out. That H&R is really pretty cool.