Glad to throw my 2 cents in as to why to go with the 3D. The Auber keeps the temp exactly where you want it to be. After years of smoking on my Weber Smokey Mountain, it's nice to be able to see the temp stay where you want it. No charcoal to add or airflow to manage. If I understand correctly, the SI non-D models all have a wide temp swing which is considered normal with the analog units. With the 3D, you'll get exactly what you set it for. Being able to set your internal meat temp is icing on the cake. The hardest thing you'll need to get used to is "Don't open the door". If done correctly, all your work is prep and you can just kick back and enjoy the smoke time. Enjoy your new smoker!
Jack