Had trouble finding anything up to date on the section on road but went ahead and did the run from Goondiwindi to Tenterfield and then on to Lismore.
We tackled it in an NT pajero diesel towing a 21ft van about 2300kg loaded.
The section through to Tenterfield was narrow and not without badly damaged sections but anything that was potentially dangerous was well sign posted, not like the liechardt hwy in QLD which was bloody woo full, from Condamine to Goondiwindi.
There is a long pull up to Tenterfield about 500m but its not that winding. Very narrow section for a couple of kms coming into Tenterfield, 80km, so drive to the condition.
Now for the so called difficult section, down to Drake. No worrys at all. Lock into 2 or 3 winding but not a problem.
The larst steep section, not real sure where now, I think it was near Mummulgum, anyhow be ready to select a low gear as you drop about 150m pretty dam quick.
Hope this helps anyone taking on the Brunxner. Its not that bad. Drive to the conditions and use your gears.