didn't have too much trouble with traffic. the road from adelaide to port augusta is dual carraigeway for the first 100km or so, then the next 200km has overtaking lanes about every 5-10km . it is the main road out to Perth, so it is a reasonable road. you still get the odd clown though.
as for the inconsiderate campers, glad that got sorted. nothing worse than trying to get away for some peace and quiet only to have it ruined by an inconsiderate so and so.
the mambray ck campground is booked mainly by families with young kids, so during the day there is scooters and bikes and kids everywhere, but not long after dark, its like there's no one there