I passed through there last May, DR came through a few months afterwards. Someone will be able to provide more recent experience, but unless they have started to work on that specific section, it's pretty soft, and more of a track than an actual road.
To describe it a bit, the first part after Okoyu is soft, loamy soil that can surprisingly handle a fair bit of rain but there will be puddles if it is raining. The main challenge is that the softness of the soil leads to deep parallel tracks left by the large trucks that ply this route. As DR mentioned, the deep, double wheel ruts cause a bike to scrap it's panniers along the sides as you work your way along.
For a truck, the challenge will be that you have two deep ruts and since it is one lane, you have no choice but to bump along with your tires in the tracks and your skid plate, etc. scraping along the center. Depends on your clearance but I would guess that you would feel like you are about to be high centered a fair bit of the time.
The second half of the road as you get nearer to the border is quite sandy. It's a lot of work for a loaded bike to ride in even moderately deep soft sand, I wasn't looking at it from the perspective of a truck but I would imagine that there are parts that you would like to have a 4X4 to plow through.
Not sure when the rainy season is there, but in May it was a bit wet, not too bad. Additional rain would make the first part worse, but not have too much of an impact on the later sandy section. For a 4x2 and not a 4x4, you may want to ask around more to see what the other route would be like. Happy planing.