questions about jayco swift baja edition(contimplating on buying one)

[pondstomper]

I currently own a Aliner ranger(love it), and tow with a 07 Colorado i5 3.7l. My wife would like to have a little more space, so I am thinking about getting a Baja edition 154bh, 184bh, 185rb. either one of these would be fine. My question is on the construction of the membrane under the trailer and the "enclosed" floor (looks more like a plastic cardboard). How well do these trailers handle offroad (fireroads, backwoods) and have any issues come up with the enclosed floor.