The thread about ribs makes me wonder, just how rare is really good barbecue? It sounds like you actually can't buy any really good ribs in Chicago, I know for a fact that there's no really good barbecue in Dallas, I've looked on the boards in other regions and never seen anyone really rave about barbecue. Even on the Texas board it looks like Black's is the only consistently excellent brisket, although opinions differ about just how great some of the other Hill Country joints may be.
From the barbecue message boards I've looked at, in particular the KCBS board, the standards of excellence for brisket, pulled pork, and dry ribs are pretty clear. The techniques are pretty simple and not secret, but I guess it's just not an economical proposition for any restaurant to do it right, because as far as I can tell you pretty much can't get any good barbecue unless you cook it yourself.