I came back from my JNB/JNB run yesterday morning. Everythin was fine. I just had a few short connections in LHR because of a few delays.
Everybody who's doing the same run I could recommend to have a steak at "The Butcher Shop" in Sandton
http://www.thebutchershop.co.za/
I did that both times and was impressed of the quality and service.