I like mine to come cleanly off the bone, but just barely and with the aforementioned little tug. It's just a texture thing with me, like steak vs. pot roast.(Not saying I'm right, it's just what I like) My opinion is that the meat is pretty tender to start with, so no real reason to braise it. For what it's worth, I've only had ribs in one restaurant that were done the way I like them. Most places they're fotb and doused in sauce.
I think the reason the comp judges look for the tug is that it's tough to get the ribs off at the appropriate temp while keeping them moist AND tender. Foiling for 2 hours with a braising liquid kinda guarantees they'll be moist, unless you overdo it on the last phase without foil. I think it's just a "degree of difficulty" thing.