The best way to tackle this route is to start at Victoria West. You can do it from Graaff-Reinet up, but somehow its not quite the same. Start at the cafe on the edge of town in Vic West (good rugby supporters venue!), ride into town and turn right after the Excel garage onto the Murraysberg road.
As you hit the outskirts of town you can pretty much twist the throttle and belt it from there. Be careful as you approach and cross the N1 highway, but after that you e back in biker Nirvana. The approach to Murraysberg is as fast as you want it.
Between Murraysberg and Graaff-Reinet your speed will be a little less, but the twisties will make up for it. The road condition is tarmac all the way, mostly with shoulder run-offs, and is currently and a good condition.
Police presence is minimal, but be vigilant 10km either side of Murraysberg and from about 20km before Graaff-Reinet.