The principle is the same and it does increase hookups cause most of you that have used hardware have seen fish follow lures and at the last minute bump or turn away.
Principle of the barrel swivel to split ring is not the same as this. I've tried both, and landing ratio goes way up with the dacron, every single time I've tried it. They both increase hookups however, and cause less injury (if a smaller hook is used with the split ring/swivel combo, which doesn't seem to be most people's case).
There are no binding points with the dacron, period. With the swivel split ring combo, there are still binding points which give the fish leverage. Try rigging a couple of each up and twist the spoon around, you'll see what I mean. While they both put the hook farther back and increase hookups on picky fish, they don't work the same once a fish is hooked.
Lastly, the dacron is much more cost effective. As I said in an earlier post, I can get 100 hooks (non open eye, regular octopus hooks) for $10. The dacron is 6 bucks and will honestly last 1000's of hooks. So you're pretty much spending 10 cents on your components. With the typical split ring/swivel/open eye hook that I've seen used (lots) you will be no where near that, and if you are, I'd love to hear what open eye hooks you use. I've never seen even just the open eyed hooks at 10 cents a piece - let alone adding in the split ring and barrel swivel cost. Maybe that doesn't bother you, but for myself, the 50 cents per spoon I'm saving when I lose one is a big deal.
And finally, maybe you're right, and you have seen this before. I personally have never seen anyone rig up a spoon with a braided trailer hook before. In my last 2 years of using it, all I get is puzzled looks on the river. It may be hard to believe, but I did indeed come up with this and start using it on my own. I don't really care if I invented it or not, it's something not very commonly seen, it doesn't get used. I wanted to bring light to it so that people could increase landing and decrease injured fish - and finally, see how incredibly easy it is to do!
Cheers