If you want to get away from the EcoDiesel, how about the 2.8L Duramax? Decent size trucks, good fuel mileage as well... or you could always trade up and get into another EcoDiesel with a warranty if you really like the platform/truck.
Agreed. Most owners don't have any problems.. Like I've said before, forums attract a lot of attention from owners that aren't happy because it gives them an outlet to express those feelings.. I don't blame them though.
Welcome!
As far as to early to tune, that's an opinion. I did my first diesel with 3000K miles on it. Never had an issue, this one is stock however so it all depends on what "risks" you want to take.
No doubt a tune is beneficial, but loosing that warranty (if something bad happen) would be...