That short mod barrel is rare. Folks are having qualified gunsmiths make them.
Lee is correct, internal geometry is a huge key in all this Art & Science.
Sad to to say, a lot of the new geometry is about marketing and hype. Just as a lot of firearm related things are. Some of the new geometry will only work "pretty good" with one type of ammo, and that is it. The whole versatility of the gun, ammo, loads is not there. For a card shooter, or slug bulls-eye shooter, this is fine, a specialized sport.
The best kept secret is still a bone stock shotgun, that fits the shooter, with the correct basic fundamentals. Always has been, always will be. Anything from Serious Situations, hunting, clay games, moving or stationary targets - can be done with one. All one does is tweak fit, get lessons, and allow pattern board to reveal what that gun, likes for what tasks. External knurled chokes just allow more fine tuning.
One reason my go-to gun, is a single shot I mentioned earlier. Personally, the more hype I read on Internet, the more I stay with bone stock. I'd actually like to go to using nothing but a 20ga two barrel gun, SXS like a 311 with fixed chokes.
I know of 4 Benellis, 2 11-87 Police set ups, 8 Wilson Combat, 3 Vang Comp - about a dozen Benelli Nova shotguns - sold. Just had to have, then once rec'd
Tested, tried and ... - owners went back to what works. FWIW 7 of the Nova's - I broke these, and one I broke twice, got it back, next broke it again, and back it went again.
Glocks do not like me either...
I know one person that used a funky sling set up and had to see the doctor as that heavy gun, hit him in privates, actually a bit of concern , when doing some Team Walrus maneuver...
My "tricked out" sling I used for my SX1 is missing. Leather Latigo if you will, just woven brown leather, round, and about the diameter of a peppermint stick. Fixed at mag cap and buttstock. Also missing is a similar one, that slip knotted over barrel and pistol grip of shotgun. I used this one for rifles too.
Quiet, enough weight to flip on, off, over head, still not heavy enough to have "pendulum effect".
My "trick" sling set up used on some other guns were Pachmayr Flush Mount Sling Swivels
http://www.lymanproducts.com/pachmayr/index.htm
I really really really like these!
I have some folks when they get ready are going to put these on shotguns, and rifles.
I understand they have indoor plumbing, and electricity now-a-days ...