So it's an optional thing to use the rings to lock in the strap, when you anticipate the possibility of the buckle failing? When it's just tucked inside the two rings, then it's acting as a retainer for the strap end, but it doesn't act in that double-secure fashion?
Does you always just tuck it in, or loop it through the rings in certain situations?
Looks like there are two versions; a two piece strap and the one piece that loops through both wrist pins- I suppose for best security the one piece is best, so the watch won't drop away if one pin fails.
I haven't had any failures of any of the straps I've used, so I would put that lower on the totem pole than comfort and appearance, I guess.