I run a cabinet like the GOSM. It's the Broil Mate Vertical Cabinet smoker from Home Depot (discontinued now I believe). Anyway. This past weekend on my large smoke, I had to run the thing on MAX to keep a steady 230F temp on the upper racks.... We had a bit of wind, not much. I found this very odd that I had a tough time keeping temps up. Vent on the back towards the top started out open about 1/8th of the way, then I had it basically all the way closed in an effort to keep temps up with less fuel, but it didn't seem to work. My digital temperature probe was up towards the top and was reading the same as the stock gauge in the door (also near the top rack). What I'm thinking is that there's just a huge temp. variation in my smoker from the lower levels to the upper? I guess I should have probed the bottom racks to see. One observation was that the ABT's on the lower racks finished quicker than those up top, which is a tell tale sign in my books. Anyone else running these kind of units and find a big variation in temps throughout the cabinet?