muebe - I had a pretty good sized chunk of hickory on the charcoal but it didn't seem to be enough.
It makes sense that it wouldn't be as smoky, even with a chunk of wood. The higher the temperature - the sooner the outside layer of meat reaches 140° - the sooner smoke absorption stops.
At 140° myoglobin denatures and the meat cells tighten and wall up stopping any transfer of water through the membrane (osmosis). Without this transfer smoke particulates and nitric acid cannot penetrate further stopping smoke penetration and smoke ring development.
Don't take this as a knock against the PBC; it's not. It's just an explanation of what's going on with a thick cut of meat and smoke.
I bet if you played around with it and started out with a small amount of charcoal and a chunk or two of wood to do a hot smoke (165° - 185°) for the first hour or two, then added the recommended amount of charcoal to bring it up to the normal cooking temp, you'd get a lot better smoke penetration, and a noticeable smoke ring
If I had a PBC I'd experiment to see how many coals it takes to get a pit temp of 165° - 185° (Hot smoke temps). Just a thought.