Swamplites are a good all terrain tire, and not really "great" at just one thing. They ride good, but do not clean out as well as an outlaw or silverback in the mud. It all depends on what you're shooting for. Are you going to be hitting a lot of mud holes or will you be doing mostly trail riding? They're a great trail tire, but if you're looking for a mud tire i'd look into some different tires.
The Swamplites tend to run right at the advertised size from my understanding.