One of my friends had a set of 37's on one of his Jeeps, and they were the fastest-wearing and most uneven-wearing tires any of us had ever seen. The tread started to immediately get cupped and feathered, and were louder than a set of Mud Grapplers or Boggers.
They seemed to perform decently in the sand dunes. Everywhere else they were pretty sub-par. He got rid of them after no more than 10,000 miles, and by that point they were pretty unusable.