I've got the SI#3....remember, this is an analog controller so much like your oven you will have the temp swing as it cycles on & off. Unless you need precision temp control, for some reason, the installed controller should suit you fine. If you are doing a 10 pound butt or 13 pound brisket the final result will be delicious with the long cook time. I set mine on 250 for a large butt, turn it on before hitting the bunk and in the morning the porch smells delicious. Depending on your budget I think the SI#4 has a built in PID, but I'm not sure. I also think smaller SI's can be had with a PID if you want that. It's been a while since I bought and I'm not totally up on new offerings. For the money, it's awesome to me. Cook-Shack quality clone without the hefty price. Again, my opinion only but since we cook to temps and not by time in the long run the controller is adequate. HTH....Willie