It depends on how much off roading you are doing. If you are trying to take advatage of the Pro Comp Deal then I would recommend the Pro Comp Mud Terrain's. The tread is aggressive for on the trails but not over agressive to where they are annoying on the road. The Xtreme Mud Terrains are also a very good tire and they have a more agrressive side wall so they would be better for more trail use but they will be louder on the road. I hope that helps.
There AT's are not that great off road.... On road they are OK. They do have a great warranty but I never got chance to see how long the tires lasted because I traded the truck with 15k on them. 25% worn and the centers took allot of the abuse no matter what air pressure I ran ........ BFG TA/KO's and Nitto Terras are a better choice IMHO..... Nitto's are better in the rain by far! BFG's will probably last longer but at $40 more a tire I will stay with the Nitto's as long as they give me good service.