I've pulled mine through some pretty rough trails, and it did as well as any trailer it's weight. I don't have many pictures or videos, just because it's usually my family and friends, and we don't make a point to walk the trailer very often. That said, it's really only the weight that holds you back. The center of gravity is pretty low, and other than that, a trailer is a trailer. It's not going to be as good as a smaller 4x6 trailer, but it certainly went anywhere I wanted it to go.
Getting to these spots wasn't something I'd consider rock crawling, but there weren't any cars getting up there either.
Don
-
This looks like exactly what I am looking for. Nice Unit!