Interstate sucks, but glad the truck is running good! My dad's old '07 6.0 was bulletproofed/deleted and mildly tuned, but man that thing was a beast. It pulled my old SAS'd 4runner to Moab doing 90 the whole way, and did amazing. Sad that some lady cut him off on the freeway and totaled it. His 2nd one wasn't near the truck the first one was, and now that UT county is back to requiring emissions, it had to have all the emissions components. He had it built the best he could be a shop in SLC (can't remember the name) but it was never the same truck as his first. That truck kept killing an injector, but the shop that did the work kept warrantying it. I think my dad finally decided to get a brand new truck for the first time ever and sold it.
I have debated the 6.0, since his first one was so amazing, but then his second wasn't. Then like you said here several times, finding good shops to work on it is also an issue. I would agree if I ever got one I would send it back east.