Skip if it you can. It is a terrible road, sometimes impassible. With a 4x4, go for it, but road trucks have a bad time of it during the monsoon season.
It is not so bad from Watson Lake, but it gets worse each mile you drive north towards Faro. I drove it a couple years ago. It is/was a decent gravel road at Watson, but it narrowed down to nearly single lane laid over every little bump in the woods. The Yukon gov't is upgrading it every year but it has a long way to go. One of the local scandals is a certain contractor has to fix the same section of road every friggin year.
There was a 1 km section of road the highway department pulled trucks back and forth with a D7 in 2013, I think, which put thousands of dollars of damage on some of those trucks.
You remember those pics of the Alaska Highway in 1942 with trucks buried up to mid-axle? Someone put together a photo montage of the AK highway 1942 vs. the Robert Campbell highway in 2013. Really similar except for the truck vintages. I tried to find it in my emails, but can't.
Check here for road conditions: http://www.511yukon.ca/textreport.html