Surely I'll get hammered for this, but here goes. The 6.0's were not bad motors...and the trucks they're in are by far the best on the road in just about every aspect. In any case...if you can drive a 6.0 with some common sense and at the bare minimum with a set of gauges to keep an eye on things. You shouldn't ever have an issue.
Now with that being said I understand that a lot of the early trucks had issues with the casting sand in the motors leading to clogs in the oil cooler...which then led to issues with the EGR coolers. Guess what...just about every new vehicle with a new drivetrain has issues the first couple years. Some worse than others of course. When you're talking about a $40,000 truck of course things are more expensive to fix...just part of the game.
I believe most of the bad wrap the 6.0's got was because people were so use to the 7.3 and being able to do whatever they wanted to them that when they got their hands on the 6.0's they threw a bunch of bolt on power adders at them, lifted them, and hooked them to the biggest load they could and then came home crying when they blew up their new truck.
Seriously...have you ever considered how many 6.0's are still in use by local governments and ambulance services. Those things get rode hard, idle most of the day and are still in use. Any business with several of them in service would surely cut losses before they had continuing issues with their entire fleet. Another way to think about it...If the internet didn't exist...how many issues would you have heard about?