I think SAA is getting themselves into a lot of trouble with the A340-300. It cannot get out of JNB on hot days with full payload. The engines will overtemp everytime and maintenance will have a great time doing boroscopes everyday. The end result is that the engine has to get replaced after so many overtemp's. So I hope SAA are getting a lot of spare engines.
I have had the pleasure/displeasure to be onboard a A340-300 out of JNB on a hot afternoon. Were taking off towards Kempton and saw the fire station appear on the left before they rotated!