Hi Smokinbee as you will bee ;>)
I've had both, the 3 and about two months later the 3D came out, sold the 3 and bought the 3D. Love both of them, depends on what you want?
Model 3 worked great, set the temperature (approximately the temperature) and walk away. The 3D is a little more to do, but very easy. I like the 3D better since it has the Auber already installed along with the meat probe. Takes a few minutes to set up, once you've done it and understand it, takes really seconds. The 3D has the ability to set the box temperature, set how long you want to cook, OR set the internal temp you want the meat to be which is what the probe does. You can also set it to lower the temperature once the internal temperature is reached so you don't have to worry about over cooking the meat.
Anyway, that is just a few reasons I like the 3D vs. 3 model, and I like gadgets so that's another reason for me to get it. I have to say the MAIN reason I like the 3D is how the box temperature is regulated, VERY precise!! I cooked some baby back ribs for our Valentines Day lunch today, set the temperature for 235 and checked it several times during the smoke, the temperature NEVER moved off 235, it stayed right on 235. The trick for me is to keep the cold meat away from the box probe, I cooked a couple pork butts the other day and I could see the temperature starting to vary ever so often. That reason was because the cold meat was too close to the box temperature probe on the back of the box. Keeping the cold meat away from the probe, a couple of inches anyway, the temperature stays +- 1-2 degrees from where you set it.
Just my two cents worth, I love the 3D and would not consider selling it like I did the 3 once the 3D came out.
Welcome to the forum and there are a lot of friendly folks here to help you out. EVERYTHING I have learned about smoking over the past 4 months has been right here and their suggestions are always great, a lot of experience here, you came to a good place for information for sure.
Welcome from DFW Texas area!
Carl