12-15 lb packers usually take me on the order of 12 hours or so. I've also not been too afraid to foil for the last hour or so, with some beef broth, a little more rub.
I've been pulling mine between 185 and 190, holding for a couple hours. Seems to me that 2 hours / lb is a bit on the high side, but that's just me.
I'm sure it'll be great.