I had the Smarty Jr and IMHO I do not see much difference between that and EFI I am using now. That is except for the 12V-single injection tune. I do see a drop of around 50-100* in EGT's and 1-2 more mpg. Only issue with it is that it is noisy as hell...lol. But for the other standard tunes they seem to run no different. BUT, I was told that EFI is more for modded trucks than stock trucks.