Well, for me, a couple of thoughts.
Ribs are great, when you can find great ribs -- not tumbled, not injected, some with plenty of fat.
As for the lower temps. There's not a huge difference in 200 and 225. The drying out effect for me is a cause of the reduced fat in the ribs. Less fat, more chance of drying out.
The thinner parts of the rib will dry out before the thicker parts, that's why the ends dry out before the middle as the don't have as much meat/fat to absorb the heat.
jka,
the papery substance on the underneat side when you're eating is the cooked membrane. You don't have to take it off but I do. Partially, because in presenting/eating, it's just annoying. I've always taken it off, not to retain moisutre, but to allow the smoke flavor and rub to penetrate. Nothing can penetrate that membrane on the underside. but whatever works for you is fine by me
Smokin'