Thanks Don and DimplesLee.
I didn't realise E. capensis was the same as E. zeyheri. Actually zeyheri is one of the many subspecies of capensis.
Would be interesting to hear if anyone has tasted it. I'm thinking it might need help from its northern neighbour the miracle fruit...
Edit: Have some good red soil that I think capensis would like, South Africa has a similar soil structure to the Australia's outback from some photos I've seen.