That is my typical arguement, as mentioned above. I'm a Ford guy, but the 6.0 just scares me, I'm needing to get another truck, and there is an 06 with 25k miles at a dealership in town I would love to have. But as far as doing any tuning to them......I've always been told by a few guys that work on them, to keep em stock and service them regular if you want them to last...so until there is a compelling arguement the other way, 7.3's seem pretty good to me. Good tuning, upgraded hpop, injectors, turbo, you've got a truck capable a whole lot for not much money if you get the truck itself bought right.
I'm a ford guy and I would NEVER buy a 6.0... alot more problems i've seen with those motors then any other motor i've ever heard of, there is a big reason ford is sueing international over that motor.