Nothing that somebody else couldn't figure out, eventually.. Most of the REALLY good places here have been doing it for decades - even into the 20's and 30's.. Its just a combo of the smoke room being seasoned over the years, the rub they put on th emeat, the technique and time put into smoking/cooking it, and the BBQ sauce they make from their own recipes.. I'm not a big fan of BBQ sauce - I like to let the meat do the talking..
So, that my GUESS.. they years of experience and fine tuning the mixes and procedures.. Lot of new places bomb out over a fe wyears and don't ever get that process just right.. Total guess on my part..
Friendship is like peeing your pants.. Everybody can see it, but only you can feel the warmth..