Thanks very much for the tips CD and mac...
After researching EF vs KVS, was really keen on EF until I saw on their website they didn't support or get data for CX.
So, I'll go the free route and sign up for Asia Miles to see what I can find there.
Read over on the CX forum that it appears the JNB route is routinely 'sold' in F, but trying to get confirmation of that, but am hopeful your experience is indicative of what I'll find.