[CO6.7Cummins]

i have run a number of programmers and just started running the XRT a few weeks ago. i LOVE it! the tunes are great. i was torn between the Smarty and XRT, and 2 things really swayed me. i feel there are too many settings to deal with on the smarty, and all of the head gasket issues weren't looking good. also i was looking in the classifieds on here and it seemed that the Smartys to XRTs for sale were like a 3 to 1 ratio. that's not good. these are only my observations and opinions, it seems there has been a bit less trouble with the XRT and certainly less parameters to deal with. some want all of those setting. i can say you would likely love the XRT tunes though. oh yeah the XRT smokes more than the others too.

To offer a different perspective, I sold my XRT and went to Smarty. Not because I didn't like the tunes. Not because I didn't like the smoke. But because of my results on a dyno.

It seems both tuners can perform entirely different on each truck. There's really no rhyme or reason to it. I just found one worked better for me.

As for which one, if the OP can try both, I'd suggest it.