It's all about how much the gun weighs, how you mount it, and how well fits you. I agree that a 5 1/2# gun could provide more recoil than one might want under high volume. But, that's not it's niche. The lightweights are for carrying all day and shooting occasionally.
OTOH, add just a few ounces to the gun, make sure it fits you, and you can shoot an unlimited amount through it without a problem. My Beretta 687 SPII Sporting weighs 6# 3.9 oz, empty. I have put nearly 1500 rounds through it in six hours of shooting doves in Cordoba, using mostly 7/8 oz. loads, with no recoil issues. My shoulder would be slightly tender by late afternoon, but completely normal the next morning. And, the thing is, I can easily carry that gun all day in the uplands without tiring.
I'm with Miller. I'm amazed at the inability of so many to handle a little recoil, nobody here in particular, and, I might add, the inability to carry a gun that weighs over 6 lbs. I understand that heart surgery and other things can be extenuating circumstances, but I'm afraid we have become a country of pussies.
SRH
Stan--What we have become is a nation where far fewer people have jobs involving significant physical labor. It's interesting to note, re gun weight, that American classic smallbores are far more sought after (and command a far higher price--both supply and demand working in their favor) than are 12's. Thus, to a certain degree, the "pussification" of this country when it comes to what a gun weighs.
I'd have no issue with your gun--and in fact carried one a few ounces heavier hunting Iowa pheasants last week--if we're talking about open country birds. But a lot of people who hunt grouse and woodcock (and who spend a significant amount of time actually IN the puckerbrush as opposed to walking trails) would probably find it a bit heavy. I would. I'm right about at my "woods gun" max with a recently acquired Rizzini 550 28ga, at 5 3/4 pounds. The stuff I hunt requires a lot of one hand carrying. Even lighter would be better, and after the season's over, I'm thinking about stock surgery to convert a PG to straight (which I prefer anyhow) and shaving off another 2 or 3 ounces. But open country hunting, I don't think 6 1/2 should be much of an issue. Remembering the guys who carried 12ga A-5's when I was a kid, that has to be a piece of cake. But then I remember what most of those guys did for a living . . .
Re recoil, I'm not particularly sensitive. But some people are sold on the idea that either a very heavy load of shot and/or warp speed velocity are necessary to bag a pheasant. The 4 I collected last week all fell to Kent Gamebore 1 1/16 oz loads. I like that particular 2 1/2" load, although the gun through which I shot them is chambered 2 3/4", and I had my "heavy" load--a 1 1/8 oz reload--available in the full choke barrel. Given all that choke, I figure that 1 1/8 oz 6's gives me all the range I both might need and am capable of using. Something like 1 1/4 oz @ 1500 fps, which is what we see in a lot of today's "premium" pheasant loads . . . no thanks. I'm sure the gun would handle it, but I might find myself flinching in anticipation. And I don't think the pheasant--unless maybe he's out there at 50 yards or so--would notice the difference.