BTW.. I brought some to the boys at BBQ Galores and the chef at AJ"s... the chef was blown away... he told me they would present that in their Gourmet dinner area.......
It really turned out nice...... took 3 1/2 hours.. I found the when smoking only a few items to go with two tiers and not to use the 3...... the third tier really changes the temp.... keeps the smoker at a lower temp over all....... do you get that too Crash?
The more surface area that you are heating, the more fuel it will take to get up to your desired temp. We just cook on the amount of stackers that will hold the amount of meat that we need.
The Excel 20 (2 stackers) temp being too low was a problem for us at first, but we think we have it dialed in now. We filled up the entire basket w/ K and dropped about 15 lit coals in the middle. It worked perfectly and stayed consistent for a good 10 hours in bad weather conditions.
You can definitely drop to one stacker, but you will be much closer to the heat source and have a higher grate temp. I'd go w/ two stackers unless you are doing a high-heat cook.