For all practical purposes to the owner there isn't any difference between the various methods of joining barrels. It comes down to what's economical for the maker. Of course they make a virtue of their method in their advertising. Many, many guns have been made using all systems and I have never read of a failure due to the particular way the barrels were joined. The sole exception I recall reading about was the bottom barrel of a Beretta coming loose and sliding forward an inch or so due to a faulty joint and I would have trouble believing that unless I saw it. I believe that Winchester copied the BSA system and then talked it up as being a better way for sales purposes. They would do that of course, wouldn't they.
nial