Other Middle East and Africa Frequent Flyer Programs - SAA or QR to JNB in Business Class?

I am flying from IAD. Which airline do you suggest flying because I am a star alliance member those 2 airlines seem to be my best option. I have heard arguments for both like SAA is the "best" to Africa but how can it be the "best" when Qatar has much higher ratings in terms of catering and entertainment. Any feedback is appreciated.

I've only ever heard good things about C class in SAA. They use lie flat beds.

Having completed 5 LHR-JNB trips in the past year in SAA in economy - there is no problem at all with this airline. As the flight is more or less direct, it has to be a better option than QR.

QR isn't a full *A airline - so you'll probably not earn tier points. Apparently their C class is excellent, but that's quite some detour!

QR is not a *A member, it has agreements with some *A airlines. You dont say which *A programme you are a member of, so I cant say how you will be 'rewarded' for using QR to JNB.
SA is the only direct way to get from IAD to JNB, so if time is important its a no brainer (17 hours vs 33 hours).
SA C is pretty good, with 'real' flat beds (180 degree). QR C is reported to be very good, but I have no personal experience.
The fare difference is also not insignificant, SA between USD 7000 and 7500, QR between USD 8500 and 9300 (from a on-line dummy booking)

Your individual priorities will dictate which one to use.

To me its a no brainer - take SA. The C product on SA is very good - many postings on FT will back up their excellent C product. And frankly QR would have to be offering something amazing to justify nearly double the time spent getting to and from your destination!