I think if you are cooking ribs at 300F, you will find that they can get done a lot quicker, not sure an hour, but, a lot quicker. Done for things like ribs is a relative term as well.
I think there are differences in the texture of meat done at different temperatures, even in terms of large cuts like brisket and butts, but, I can't quantify that to be true, just my feeling. Certainly, I prefer ribs that I have cooked at a temperature of 225F to ribs where I couldn't get the temperature down where I would have liked. I think hanging may increaser convection, which would also play a role in cooking time.
I'm feeling bearish, and I'm packing a Wusthof Grand Brisket slicer from MABA
Whip It Off, Chambers!
"perhaps...but then again...maybe not..."