I bought a Diablo first and couldn't get it to download the tune to send it to Hemifever for a custom tune. I think Windows 8 was a big problem on my new computer. I was able to download the performance tune in my truck and wasn't really impressed at all. But it wouldn't let me do it a second time. Turns out I didn't have to put truck back to stock for him to tune it. I sent it back and bought a Bully Dog from Moe's Performance and it's a lot better. At least it is in MY truck. Noticeable difference between the two. If you want a custom tune, then Hemifever will sell u a DS with his tunes and they are supposed to be awesome. If all you want is canned tunes, then the Bully Dog is probably better for that. It's smaller than the DS, too. I personally like the BD features better and it's easier for ME to use. They sell a pillar gauge pod that works for either one. I have a Diablo mount for that gauge pod that is brand new I will GIVE to anyone who needs it if they will just pay to have it shipped to themselves. Just email me the shipping deal from FedEx or whoever and ill ship it.