Is the 6.4l engine really as bad as everybody says it is? I hear about all these things that can happen but I want some more input.
I've owned (5) of them and have never experienced any problems other that having a heater-blend door replaced.
My current 2010 F250 Crew Cab Lariat 4x4 with 47,000 miles has been the best truck that I've ever owned. It, like the four others, has had the Diesel Particulate Filter removed from day-one and I've run a Spartan DashDaq tuner with 250 tune.
The early 2008's (not mine thankfully) had some radiator problems, but other than that, it's been pretty much a Bullet-Proof motor. Of course, if you dial-up the tuner and keep your foot in it all the time, you will probably blow the head gaskets, warp the heads or worse.
As far as a "stock" truck, my friend's 2009 with 175,000 miles on it, hasn't ever had any drive-train related problem. He also pulls some heavy trailers & equipment behind his truck, so it hasn't been "babied", but it has been well maintained. The only penalty that he's paid keeping the truck "stock" is at the fuel pump. The "tuned" trucks do get better mileage, but don't believe the stories from the guys saying 15 in-town and 23 on-the-highway. It ain't going to happen!