Hi Top.ender,
I have the delux off road extreme, I think thats what its called.
As a basic camper for my family it works ok. I have dragged it from South West Rocks, up through to Agnes Waters and back again to Noosa. As well as other smaller trips. If you are going for one of these make sure you check it out before you buy. They sell / used to sell a Shiteload on ebay so you really want to go and look at what your buying before hand. The trailers are chinese imports and the same trailer can be seen on here in various threads, however it appears different importers carry out different amounts of work when they assemble them in OZ. For instance Aussie Blues one is very similar to mine except the draw bar and base are just bolted on. ( See this thread http://myswag.org/forum/index.php?topic=14982.0 ) Where as the one I picked up from market direct is welded, I have rewelded the drawbar etc to strengthen it.
I am planning to do a trip in the next couple of months from Noosa out through Cararvon on to SWMBO's parents farm between Blackall and Barcky and then on to Winton to take my youngest to see the dinosaur tracks. So that will give it a pretty good work out, but I dont think I will see anything like what you see on the Gibb River Road in terms of conditions.
If you want any pics or info about them I am happy to answer your questions and post pics and stuff so just let me know.
Cheers and happy hunting..............