SO, I got to try out my new tires yesterday on some nice muddy trails, including some good slick hill climbs and descents. They were awesome!!
I started off the day automatically doubting how they'd compare to the Swampers, but I was more and more impressed as the day went on, as I didn't have any issues with traction at all. Even being the last truck in a line of 18! (you know how the guys ahead of you always slick up the muddy hillclimbs leaving the last guy with nothing to grip?)
The huge tread voids provide great grip, and they clean out the gooey stuff extremely well. Even when they were completely packed with clay-based muck they never turned to "slicks" always having some clean tread.
Here are a couple pictures of the tires completely packed with mud. This is that really heavy sticky clay-mud that sticks to everything like glue. But even with all that crud they still had about 1/4" of tread depth, and they cleaned right out as soon as we started moving again.
Also, the tank-tracks they leave are pretty cool