I've flown SAA hundreds of times over the years and only ever had a couple of bad flights. I've flown Kulula maybe 10 times in the last few years and each experience was, at best, mediocre. I find their forced humour, which most of the FA's really can't carry off, childish and irritating.
In fairness though I must give them full marks for trying hard to make the experience more entertaining - I just don't feel they achieve it.