A little over 8 lbs, 17 hours...not unusually long. 1.5 - 2 hours per pound is a good rule of thumb, but not an exact science. Funny thing about large cuts of meat, like butts and briskets - they're made by animals, and they're all different! Lots of factors effect cook time: the density of the muscle (Arnold Piginator, or Couch Potato Pig?), the amount of fat, and the connective tissue. If you plan to use your supplier on a regular basis, you might keep this in mind. Typically, meat you buy from a particular source is pretty consistent, as far as quality of the meat.
Next time, I'd recommend starting the butt at 240 instead of 225...this won't hurt anything, and will probably speed the cook time, without sacrificing tenderness.
Overall, sounds like great results! Anytime I hear "better than any BBQ places," I know we have a winner!