we have a cape york hard floor camper trailer, and have had it since 2005 and have not had any leaks inside, so I can highly recommend them. A friend has the australian camper trailer built at Caloundra and has done 2 years travelling in it and also loves it, so if you do decide to upgrade to the hard floor, just do your homework, work out what features you want and have a look at a few first before you buy. I looked for 12 months (my hubby started building one, but run out of time before our big trip, which was subsequently stolen from our carport) and saw the cape york and it had everything I wanted.
It even made it in and out of the road to Mitchel Falls without a hick up. Have done over 20,000 klms in it and it is still going strong.
I love my cape york, has everything I wanted in a hard floor trailer.
If you decide to keep your soft floor, good luck in sealing out the dust,