All of the advantages of Foster style slugs, longer range, greater stopping power, deeper penetration, penetration of intermediate barriers, pale in comparison to the advantages of the newer sabot slugs fired through a rifle barrel. I've popped quite a few deer with Foster slugs though both smooth bore and rifled barrels and also quite a few with sabot slugs through rifled barrels and the differences are huge.
I am always reminded of my friend who swore by Brenneke Magnum slugs. His "proof" of their superiority was that he once shot a buck at 75 yards and hit it in the ass and it was unable to run away and he was able to close the distance and deliver 2 finishers at 10 yards or so. He told me this while we were sitting on a field edge during a drive. It wasn't too long afterwards that 2 deer came out of the wood line opposite of us at about 150 yards. One was a nice buck and he was saying how if it got closer he was going to "open up" on it. I didn't give him the chance, I aimed at the center of the heart/lung area holding on the second crosshair and touched a shot off. The buck took off running and my buddy was saying "You missed, he was way out of range, you should have waited" and in the time it took for him to finish that the deer did a leaning crash into the corn stubble. He was in disbelief and questioned whether one of the drivers had shot it before it came out of the woods meaning it was wounded and I didn't actually hit it. When we got to it the shot had landed where aimed and had blown through the deer leaving a fist sized exit. The next hunting season he showed up with a new shotgun with a rifled barrel and a scope and carrying the same slugs I had been using.
Rifled barrels make buckshot patterns open up considerably though so remove the advantage of being able to use buckshot interchangeably, but if I had to face an armed person, I wouldn't feel at a disadvantage launching slugs at their vitals, even if they were behind "cover". Those sabot slugs will pass through a car door or windshield easily and make a mess out of what they find on the other side.
I am always reminded of my friend who swore by Brenneke Magnum slugs. His "proof" of their superiority was that he once shot a buck at 75 yards and hit it in the ass and it was unable to run away and he was able to close the distance and deliver 2 finishers at 10 yards or so. He told me this while we were sitting on a field edge during a drive. It wasn't too long afterwards that 2 deer came out of the wood line opposite of us at about 150 yards. One was a nice buck and he was saying how if it got closer he was going to "open up" on it. I didn't give him the chance, I aimed at the center of the heart/lung area holding on the second crosshair and touched a shot off. The buck took off running and my buddy was saying "You missed, he was way out of range, you should have waited" and in the time it took for him to finish that the deer did a leaning crash into the corn stubble. He was in disbelief and questioned whether one of the drivers had shot it before it came out of the woods meaning it was wounded and I didn't actually hit it. When we got to it the shot had landed where aimed and had blown through the deer leaving a fist sized exit. The next hunting season he showed up with a new shotgun with a rifled barrel and a scope and carrying the same slugs I had been using.
Rifled barrels make buckshot patterns open up considerably though so remove the advantage of being able to use buckshot interchangeably, but if I had to face an armed person, I wouldn't feel at a disadvantage launching slugs at their vitals, even if they were behind "cover". Those sabot slugs will pass through a car door or windshield easily and make a mess out of what they find on the other side.