Having just completed the South Africa and Zambia trip I can tell you it is ... absolutely fantastic. You may just find yourself standing on a bridge, soaked to the skin by the Zambezi, grinning like an idiot. Game viewing in SA was amazing. The only negative is that there isn't really any time to take in the cultural and historical opportunities in Cape Town. That's completely minor, though. Oh, and SA is really cheap. Tip : you require a very specialist travel adapter - buy at Heathrow.