I had Transforce AT on my 2500, even brand new, completely useless in Mud Or Snow. I put on Duratracs as that is what I have run for years, after trying a whole host of other tires. They are a good all round tire and work excellent in mud, snow and decent on ice and paved roads. They have thee 3Peak rating for areas that need that. My pickup spends about 30% of its time on pavement, the rest off pavement. If you spend more time on pavement, the BFG All Terrain/KO2 are a great tire.
If you run a lot of heavy/deep mud, I would suggest BFG Mud Terrains, get them syped so you can run them year round. It is what I ran on my serious off road rigs like Landcruisers, Jeeps etc that went way back off main roads. The pickup I don't push as hard off road, they are just too wide and too long for serious back trails, river and beaver damn crossing so when the trails get bad enough we just unload the quad and use it. It will go places with ease that you would beat hell out of a $90,000 pickup even trying to go the same places.