I've got a Weber Smokey Mountain, which is kind of barrel-esque. It's great - I can manipulate temps if I need to but I'm comfortable doing long cooks where I take the first hour or two to set the vents and then go to bed; it'll hold temp for hours. I have the 22.5" and a full load of charcoal will allow me to cook for up to 14 hours without replenishing fuel. Another side benefit, if you like to grill with charcoal (like me), you can remove the middle section of the smoker, place the grill on the charcoal ring, and grill VERY close to the coals for a great sear. (It's creating a virtual kettle grill.)

My understanding is that a PBC is more of a "set it and forget it" cooker but also gives you less ability to manipulate temperature. I've read it can run a little hotter. I don't understand how hanging vs laying changes the cook but it sounds like the PBC does a great job. With less effort that makes it pretty attractive, especially considering the cost.