I've never measured shelf-to-shelf temps, but have never had a problem with anything cooking differently enough to make a difference, between shelves. You said you see the shelves aren't really big enough for full briskets: Where do you buy your briskets? I've never found one that wouldn't fit in the 21 1/2" depth of the model 3! Btw, the price on the 3D is $699; the 4D is $1699. The shelves on the 4D are 18 1/2" x 22"...not much you can smoke that won't fit on that! It's a monster, and really more for commercial applications.
I read that the temperature in one of these holds the set temp within 3 degrees, which is great. What I want to know is how much temperature difference is there from shelf to shelf?
I also see that the shelves aren't really big enough for a full sized brisket. I would think for $1700 you could get a whole brisket in. ;)
In fairness to my comment about a brisket fitting, I was at Restaurant Depot last Saturday and I picked up a couple of briskets that, just eyeballing them, and comparing to my tape measure when I saw the size of this smoker and grabbed it to see how big that is, it just seemed like the full packer brisket was longer than 22".
I've never measured shelf-to-shelf temps, but have never had a problem with anything cooking differently enough to make a difference, between shelves. You said you see the shelves aren't really big enough for full briskets: Where do you buy your briskets? I've never found one that wouldn't fit in the 21 1/2" depth of the model 3! Btw, the price on the 3D is $699; the 4D is $1699. The shelves on the 4D are 18 1/2" x 22"...not much you can smoke that won't fit on that! It's a monster, and really more for commercial applications.
Oh, and temps, on the D models, hold within 1-2 degrees, but mostly dead-on.