Argo's are very popular in Scotland where they are used extensively for recovering deer carcasses.

Having been a passenger in one numerous time, I have seen them driven on ground that was considered to steep for quads..

Not sure how an argo stacks up against a S&S, but I would guess it has less ground pressure for a start.

That said, I would not buy a 6 wheeler as I believe they are simply too small...the 8 wheeler I the way to go and even that does not have a huge cargo area...