Ditto the Fireboard. I have one with 6 probes, and I learned more about bbq temperatures in the first few cooks than I had never known or had wrong. For instance, when you are looking, you ARE cooking. Your Traeger will come back to temp almost immediately, and the slope of the probe temps won't change.
The best thing is the ability to save your sessions with the graphs and notes, It does this automatically, so you can go back and see how you did that super turkey last Thanksgiving.
My only complaints are that the support pages are a little hard to navigate and the colors of the graph lines are too hard to distinguish for my color-blind eyes. Also, it has a grill management function for setting up custom cooks, but sadly it won't work with Traegers.