Not quite answering the question, I've done SAA, LX and LH recently EUROPE-CPT/JNB. Found SAA to be the best (generous, better than BA flat seats), followed by LX and then LH. The "trick" with the lie-flats (LX) is not to flatten them (completely), unless you're going to lie on your tum. LH had old-style seats last November on the FRA-CPT run.

On a related note, since prices were mentioned, I noticed booking LH flights via the LX website, that you can do LHR-JNB for 1600+odd pounds in C - quite good by UK pricing standards, I would think.
(LH / SAA operate codeshares on Germany-SA routes)
Rgds
Marvin