I'm not upgrading tire size at all. The two stock options for my truck are 265/75r16 or 235/85r16. Both come out to a little under 32" with the 265 being a 10.5 and the 235 being a 9.25 width. As for measuring true to size, I've seen plenty of BFG, Goodyear, etc measure under size.
I prefer the look of an all terrain, plus I take my truck hunting or a bit up the trail with my ATV's being dragged behind it. I wasn't impressed with these BFG Rugged Terrains at all. I just confirmed with my friend whom I bought the truck from, they have maybe 33,000 miles on them and are basically at the wear bar. They were ok in the snow that first winter/spring but were pretty horrible this last one. There is probably a reason BFG has discontinued them.