Finally test drove a 2014 with the vibrations.
The salesman thought I was nuts for demanding a drive on the turnpike, but he headed back inside and grabbed a dealer license plate for the highway.
Once at 75 MPH, sure enough I said 'well, there it is... I'm sorry, but this is a non-sale."
To which he replied "Yeah, I feel it."
Damn, this thing was the right price and the right year/engine, and ran like a raped ape. But I ain't gonna buy no shaker unless they dropped the price unusually low. Like $16,500 out-the-door for a 2014 used truck.
They'll find some ghetto fool that will drive it around at 45 MPH, like it, and buy it I'm sure.