Cooking steaks at a low temp until it is about 10 degrees short of your final internal temp and then finish over very high heat is called the Reverse Sear Method. It is a really good way to be sure you lock into that internal temp on you finish product. The only thing I don't like about it is the simple fact it includes an additional step and with my set up that means the use of 2 cookers. You could also bank your charcoal to one side of any old grill and do the low temp cook on the opposite side and finish directly over the coals. I don't think this Tri Tip could have been any better but I doubt the Reverse Sear mehod had anything at all to do with it.