I have the BWS Party. At first I was having trouble with temp control and was instructed to do the following. No more problems. I can now do long burns and keep the tmep within 15 degrees of target temp.
Start with a full load of charcoal in the fire box, all vents wide open and water pan out of the smoker. Light fire in one corner (I use the front right because it is eaiser to get started. I also add several chunks of wood at this time.
When you are within 25 degrees of target temp add water pan and hot water. Close the vent opposite to where you started your fire completly. Close the top and other side vent halfway. Once you hit your target vent close these vents even more. I normally run the one bottom vent open only an inch once my temp is correct. Of course you will have to adjust these vents when you add additional charcoal.
On my party any major shift in vent openings usually takes about 10 minutes for the temp to change - up if I open them or down if I close them.
Hope this helps