I have a '05 with 2500+ miles on it. I have had no true problems with the truck so far. The only "annoyance" I have is that when you clutch to downshift the 6 speed, if you let it fall to idle, it will "hunt" for idle for a couple of seconds. What I mean by hunt for idle is that it will drop to 600 rpm, return to 850 rpm (normal idle), drop to about 600 rpm again, return to 850 rpm. It may do this cycle up to 4 times before it settles and stays on 850 rpm.
Mine is a 4X2 and I have no vibration. The vibrations IMO appear to occur more with the 4X4s... Just My Observation, not a proven fact.
FYI... the lift pump is now in the tank like on the gassers. Time will tell if this is a good thing.
I am very happy with the truck. I will be glad to answer any other questions you have.