OK, so we were smoking (again!) a ham,at Sterling's house, for Christmas dinner. Since we wanted to do some work on his UDS, it was in his Excel20. After about an hour or so, we couldn't keep the temps at the 350 degrees F, that he wanted. (Since he's 6'3", we had a second stacker on it. I usually do the same thing, even though I'm only 5'10". {yes, he got to the table before I did, as a kid.})
So, the lower stacker cam out.
A short while later, after we were done with the fabricating we were doing on the UDS, ()e originally cut the head off the drum, with a drum cutter, which is an overgrown version of that old-fashioned can opener that you'd rock against the top of a tin can, except this one cuts off the top, and the seal.) So, we wrapped a piece of plumber's tape and a turnbuckle around the drum, to establish a flat plane, and cut the edge with a brand new angle-head grinder with a cut-off wheel.
No sooner were we done, than we noticed that thee temps were dropping again, even though I kicked the ProQ, to knock off the ashes. (I shook the firebox a couple times with little results.)
Well, since the UDS was done with it's changes, I said, let's switch over. We dumped the firebox, into the UDS firebox, moved the ham over, and the rest was history.
Basically, the UDS works better than the ProQ. Holds temps more stable, and also responds more quickly to adjustments. I think both of these symptoms come from the lack of air control on the ProQ. I think it leaks air too much.
Oh, after we pulled the ham, closed all the vents. 2 hours later, the lid was still warm, but the base was dead cold.
Both my ProQ, and his Excel have issues shutting down the coals. The next day after a cook, my Excel is still at 150 degrees F. My UDS is cool in 3 hours. (And, it still has the ragged "drum cutter" top edge.)
Just my opinions, guys.
steve