Hi DG, we had a similar decision to make a few years ago. Our softfloor was great and would go anywhere we could take the 4wd! But with two very young kids, we just were not using it, we found it very slow and difficult to setup for one person (while the other kept the kids amused). For us with very young kids, we had no intention of doing the tough 4wd tracks, but still love bush camping.
The fact that you are planning an around oz trip it the most exciting part for me, not which camper. Keeping your existing one sure leaves a lot in the "travel" bank account, compared to forking out for a Jayco/Goldstream.
It really depends on your situation, kids, finances, intended use etc. One day, when the kids are older, i hope to get back to a real off road camper trailer (probably not soft floor), but for now the Jayco gets us out camping nearly every second weekend, way more than we used the softfloor and would suit a big lap for us (one day
).
Good luck with your choice, personally i think you can't go wrong either way (A LAP AROUND OZ WHOO HOOO!
).
KC