The trannies are really awesome, but thats the only thing in my opinion, And yes sometimes there are a few good 6.0 here and there consider yourself damn lucky if you have one, no im not just talking out of my ass here i have worked on a couple and it made me want to burn them i hate the stupid things, one of my real close friends has an 03 model its overall been a good truck the only thing we replaced is the turbo and an icp sensor, but other than that no real problems,- this truck just hit 90,000 miles
Then i have another friend with a 6.0 i havent personally worked on it, but he has replaced everything on it, turbo EGR delete, running the 3rd set of head gaskets in the engine as we speak, and the second set of injectors, oh yea and the heads are studded, bought brand new ARP studs everytime he replaces the gaskets

At the moment he is trying his best to sell the POS because something is weird about it, it wont idle right, it kind hunts for IDLE and he is fed up with it and i dont blame him, yes it has a tuner in it EDGE IIRC but thats the only real mod besides the onther mods to try to get it to stay together, this truck has around 150,000 on it
He is lookin to replace the 6.0 with a 7.3 powerstroke