Did you say corrugations? Speak up I can't hear you over the road noise!
One time I was on it the road between Kununurra and the Gibb River Rd was one of the worst roads I've been on, 250km at <40km/h. Other notable corrugations were the first time on the road to the Wolfe Ck crater and the road up Cape York at the end of the dry. But I was on the Knx-Gibb R rd in April one year and it wasn't too bad. Also the second time on the Wolfe Ck rd it was like a baby's bottom. It just depends on when was the last time it was graded.
Apparently if you want to see corrugation try the Gunbarrel Highway or the Anne Beadell Highway - those roads have not been graded since the 1950's. You either travel real slow (some reports suggest 15-20km/h) or break things (plenty of reports of blown shockies). They are supposed to be worse than the Canning Stock Route. I hope to do the Anne Beadell and Connie Sue on my long service but it's still up in the air. If I do I'll file a report when I stop shaking. Meanwhile ....
http://www.youtube.com/watch?v=IKQmaMLI2Hs
http://www.youtube.com/watch?v=NqHkFyGsZQA