I use to have the bully dog, I really wish i would have gone strait to the DSP trinity. The driving coach is nice. I saw an improvement in my mpg when i used it, but the fact of the matter is that the performance setting gave a noticeable improvement on throttle response and power so the mpg saving went right out the window. My trinity offers all the monitoring the bully dog did except the fuel saving aspect. I just accepted that i drive a truck and the MPG will suck. My DSP has a windshield mount and it works great. However I just mount mine to the upper left corner of the gauge cluster so i don't advertise that i have a 600$ computer attached to my windshield for the passer-bys looking for new toys. Also if this is your first mod the DSP allows for custom tuning later to really bring out the power of all future endeavors. From my personnel experience I would recommend the DSP.