I ran a set of 31x11.5 LTBs for a couple seasons. They sound like a crop duster on the streets, and work like crazy on the trails. I bought them used at about 80% and they wore pretty quickly even on a "fun" truck that only saw a couple thousand kms per year, but the off-road capabilities were still really solid even when I sold them at about 50%. My buddy bought them and more or less used them up... still worked well until the end.
It's pretty much impossible to wheel in Alberta and not deal with mud, and the LTBs had no problems. Roots, shale, loose dirt... they got me through.
They did flat spot pretty badly, but it went away before long. I used 12oz of Airsoft beads in each, and they were surprisingly smooth on the highway. Really bad on wet pavement, and a waste of rubber on ice, but those aren't the reasons that one buys LTBs.