I have a BWS Extended Party. I got it about a month ago. I'm still learning it but it seems to maintain a temp with no problem. I fill it with water and leave all the dampers open. It's been taking about an hour to hit 250 but when it does I close the 2 floor dampers to about 1/8 an inch and it cooks steady at about 250. My problem is actually too much smoke flavor. I'm still experimenting to get just the right amount. And as far as the bark I just leave it on the top rack until the bark sets and haven't had a problem.
WSM / BWS Extended Party / KCBS