Follow up - picked up truck last night.  Girl drove the truck home and
commented that it drove better, I thought she was nuts because the
vibration didn't show up until about 65-70 MPH.  Well today I needed to
run to the store to get some stuff to unclog my head (MY head, not one
on any of my vehicles!) so I took the truck and I saw what she meant
immediately.  Despite all the reviews I read of the Michelins having
soft sidewalls the ride felt noticeably firmer and there was less body
roll in the corners.  I took the truck out on I-66 for a quick blast up
to speed to see if the vibration was gone, and holy heck it drives like
a new truck.  There's a little vibration through the steering wheel but
it feels more like that little transmission of engine vibes like you get
on an old BMW, or maybe it's the tread of the tires, in any case it's
not offensive and doesn't move the steering wheel at all like the old
tires did.

The old tires were "Power King All Position" FWIW.  They were LT rated
but looked awful squishy even when pumped up to 40+ PSI maybe that is
why the new Michelins feel so much better.  Old rear tires were
Michelins, those were replaced because they were starting to weather
check badly on both the sidewall and tread.

I only did one quick (well, as quick as you can with a 300 pushing
against a really stiff headwind) blast up to 70 MPH to verify lack of
vibes, because as soon as I got going down the highway a sleet storm
came up and apparently even new Michelins won't keep my truck from
getting blown around when a 40+ MPH wind shifts around to the side.
Just a bit squirrely...  I waited until the wind died down briefly,
checked for proper operation, got off at the next exit, went home, am
now happily on couch with coffee in hand.  Much better :)

nate