I was on that highway around Sept 20/13 towing my 35' fifth wheel going South to Jasper.
Most of it is pretty good particularly the North half from Grande Prairie to Grande Cache. The South half from Grande Cache to Hinton has been repaved in spots and there are a few rough patches but not too bad overall.
The South half is lacking shoulders in many sections, the North half has shoulders.
I would travel it with an RV no problem. It has improved in the last 10 years. I used to live in Dawson Creek BC and travelled the road quite a bit on the way to Jasper Natl Park.
Watch for wildlife. Lots of roadkill. Also a lot of oilfield truck traffic at times. Worse in the winter though. Although I assume you are heading up to the Alaska Hwy next year in the Spring/Summer???
Grande Cache is the only fuel/food stop between Hinton and Grande Prairie so plan accordingly.
Gregg