There is a difference in my mind - between tactically oriented "fighting shotguns" ....and a gun you might need for "defense". I think there are a lot of tactical shotguns ...with extended mags, 18 1/2" barrels, fixed open chokes ...that when new, guys put 20 - 30 rds thru them ...maybe even took a "tactical" class with them ....but now they just sit in the safe or closet..and rarely come out. All of my son's buddies ...read all the magazines, and they all bought a version of the 870's in tactical dress ...and not a one of them has fired them in a couple of yrs. I know because I pick on them ...and ask ..when I go down to see them.
I rely on my handguns for "Defense" as well ...and I train weekly with them / and have a lot of confidence with them. By all the studies / we know that a typical "defensive situation" will be over inside of 30 sec ....vs going to a "gun fight" that might last a long time .... I let the cops go to the "gun fights" ...I'm only concerned about "defense" ....and most any shotgun / even with a 28" barrel --- can handle some "defense" ...maybe not optimally / but adequately.
The tactical stuff is cool / if you like it ...but not practical for anything else in my view.
In general / I have shotguns - pumps, semi-autos, and Over Unders for shooting clays targets ( Skeet, sporting clays and Trap ) and for some upland bird hunting. A gun that is a little heavier and a longer sighting plane ...is beneficial in tracking a target flight, making a smooth swing, executing a shot, and a smooth follow thru. Shorter and lighter shotguns tend to be "whippy" and make a shooter "slap" at a target vs being smooth. So a 28" or 30" barrel is what I like / and even out to 32" for Trap ...which has less hard left or hard right angles ...
Most of the tactical guns ...do not have screw in chokes. So you're stuck on the size of the pattern you will get a 21 yds, 35 yds, etc ....vs changeable screw in chokes that change the constriction of the barrel ...and give you a different effective pattern at the kill range you need for clays or birds.
A good pump gun / with a 28" barrel is a good long term investment -- I still have the Browning BPS's Hunter models I purchased in the 1970's ...still solid guns. They killed lots of clays and birds ... / even though I've moved on to more specific Over Unders for my primary Target Guns ...where durability is an issue ( less moving parts, etc ) and I might shoot well over 10,000 shells a yr.
If a gun is real light ..and I'm 6'5" and 290 lbs ...like a Benelli semi-auto that I have ( the Super Sport - its only 7 lbs ) then I will always go with a 30" barrel to help counter-act that light whippiness. But if I go too long ...like on an Over Under Trap gun --- where I like a gun that is around 10lbs and 32" barrels ...it gets too clumsy for a quicker game like Skeet or hunting Quail. It feels like I'm trying to swing a big ole sewer pipe ...and I'm constantly behind everything ...
I have buddies that are 5'10" and 160 lbs ....and they stay with a 26" or 28" barrel on many guns .../ so it kind of depends...
60 yrs ago / before screw in chokes ...we had "grouse guns" and "pheasant guns" and "duck guns" ....because the chokes were fixed at Imp Cycl, or Modified, or Full ....and today we can all have one gun ( like a pump with a 28" barrel ) with 5 or 6 screw in chokes ....and you can shoot Skeet with it on Fri / hunt ducks on Sat / and shoot sporting clays on Sunday.
When I travel by air ....I only take one gun ...the Benelli Super Sport in 12ga, 30" barrel ...and 5 chokes ...and it does everything pretty well ...