I do not have any tortoise or other lizard, but I am interested in them. Here is my opinion on hardyness of these tortoises.
Most hardy: Chersine angulata
They are the most hardy torts from all. The imported ones have a survive chance over 70% in good enclosure (for Ex. an succulent glasehouse for Kalahari plants). It exists minimum 1 breeding colony here in Czech Republic, last week I have read an offer for CB2004. But origin of parents is problematic.
More sensitive: Homopus
They are sensitive, the survive chance for imp. animals is around 20-30% (in really good conditions), but if they survive first 2-3 years in captivity and are in good condition, they can be a long time pets. I do not know about breeding succes in CR, here are kept mostly only individual animals.
Most sensitive: Psammobates
Their survive chance for imp. exemplars is 0-5%. The most of them die in the first year, only a few animals have reached 3 years. Even a ZOO in Plzen had no succes with them. In 1999 were found 38 Ps. oculifer and 22 Ps. tentorius in an packet from SAR. They were kept in the botanical part with very sensitive plants from south Africa and today is only 1 exeplar still alive.
Some individual animals are among privat breeders, but with high mortality.
Jana