Mostly, the road is pretty good, with some less than ideal conditions on the NT side of the border and some corrugations that might appear anywhere at any time.
Mostly it depends on your patience and ability to drive slowly if conditions are poor.
Just a note.....
If "Pakrak" refers to how you carry some of your gear, I strongly suggest you find another way and leave it at home.
Pack racks are notorious for failing on less than perfect roads.
Because we have a SUV not a full 4wd we reckon on taking it easy. One query is on the suitability of tyres for both the camper trailer and on the car. The c/t is a semi off-road. Maybe good preparation is the name of the game. Advice is most welcome.
Did this trip in reverse in the middle of the year in a semi off road van. A great trip. As already stated the WA section of the road was generally pretty good but over the border it is considerably more corrugated. Plenty of places to free camp. Remember you have to get WA and NT permits (online) and you only get 3 days to do the WA section.