OK, set it all up (took about 20 mins, bit of a pain but I'm hoping to store it on the wall in one piece for future use)
Put the rug on it, presprayed it, went over it with my large Multiwash, and extracted it - no problems at all!
I didn't flood the rug so it hasn't had a huge weight over the whole face, but so far so good!
There are about 4 little pegs on the underside of the panels (for digging into turf) which I don't think will last long, but they didnt cause a problem on this outing.
I've attached a few pics to show the layout, and the amount of ground clearance it gives.