i do loin ribs almost exclusively, usually st. louis trim, always at 225. my wife likes fall off the bone style (allegedly happy wife equals happy life) so i typically do 3-2-1 method and at the end of that 6 hours they are fall apart tender.
i prefer having to tug off the bone a little, so when I do it my way w/o wrapping it takes an additional 1 to 1.5 hrs to get the tenderness.
plan for the longer time frame and follow jay's method in case they get done a little early and everyone will be happy