I finally got the AT tires I've wanted for the truck since I bought it about 18 months ago. Canadian tire had a very good sale price on their Motomaster Total Terrain AT2s, $142.49 each, $660 CDN with all taxes and enviro fees in, for the set of 4. I had a local shop install and balance for 1/2 what Canadian tire quoted. I gained between 3/4" and 1" of ground clearance, and of course much improved traction on the trails than the all seasons that were on the truck when I bought it. A bonus benefit is that the Cobra cable chains for my GMC 3500 now fit the TB as well, though I have to cinch them up to the very last catch to get them tight enough.
My impression so far is that they hum a little at low speed, but are no louder than the old Hankook all seasons at highway speed. I'll update info after I get them out in the wet, in snow, and on the logging roads. I'm sure they'll do much better than what was on there before.