IRS is a wierd thing. but im with stan, i think for high speed running, ie dunes, then the swingarm would be waaaay better. now your pathfinder armada, that suspension prob rides like a cadillac. but i dont see it performing as well as a swinger. not to mention the inherent body roll. if they wanted to do something really trick theyd run trailing arms. thats the best of both worlds.
do you mean like this guy