If you plan on racing alot, and plan to go faster than low 12's I would recommend DS. If you are only going to be racing 2 or 3 times a year and have no intention of going faster than low 12's, TL is a great product. I really loved the boost sensing hardware with TL and it was the first scantool I ever used am I'm glad I used it before DS. The amount of info that comes out of DS is almost mind-numbing.