I have a superchips traildash that I really like. It's really easy to switch between tunes and change settings. Also, it has a lot of realtime information displayed. You can pick which things you want it to show you and it can be used as a back up camera. I did notice a slight gain in MPG from their 87 tune. Tried the premium tune once. I noticed a slightly better performance, but not enough for me to keep pumping premium in my tank. I'll be running the Diablo soon. We'll see how it compares function wise soon.