Easiet route is from Babusar top. The road is bumpy from Paras up to Naran due to 2-3 small dams under construction in that area.
CPEC Route: Motorway up to Thakot. After that long long route to reach Chilas and road condition is not good (Dasu to Chilas). They block the road for almost 2 hours in the morning and evening for blasting in mountains for Bhasa dam. Simply add round about 10 more hours to reach Chilas from this route.
The road from Chilas to Raikot bridge is the worst thing on the trip to Khunjrab. From Raikot to Khujrab best-carpeted road.