Let's start over......
The Trailgrapplers would be a better choice of the two. Quieter on the highway and they'll last longer. Toyo MT's are a good tire also and since Toyo makes Nitto tires both are real good. Just remember mud tires are real heavy and may cause you to lose 2 to 3mpg.
I'm leaning more towards the Trail Grapplers. I heard the Mud Grapplers are loud.
I had a co-worker that had them on his F-150 and you could hear him coming from about a mile away. Sounded like a helicopter. They are some bad looking tires though and for a show truck or one that does a lot of offroading they are the tire to beat. Most are worn at 25k miles.
I have about 21,000 on mine and they still look like new also. Kinda has me bummed though, I want to get 33" Trail Grapplers also but I want to wait until the Terra Grapplers wear out.