Why is it I've yet to have a shoulder last the 1-1.5 hours per lb? It seems like I've hit 45 minutes or so per pound three times now. Tomorrow is the first time I'll have to be sure it's ready, and even with a 6-ish hour "resting" window, I'm not sure when to start it. It's a 9.5er, and I'm thinking midnight tonight, so it'll be done by at least ten or noon tomorrow, and then ready to eat at about 4pm, but what if this one is done at 8 or 9 in the morning as well? Does it have to do with fat content, butcher or chain, or what?