How about I buy something and it just works well? I'm in the coverage area and got one of the routers they were selling with it.
I have used Telkom mobile a few years ago here. It works. I'm just used to the faster speeds now from Vodacom but they are expensive (at least 50Mbps). I have also tried MTN (supersonic) and Rain here as well a couple years ago. Both were so terrible that I had to return it within the first week. At least Telkom still works but it slows down a lot in the evenings so it's probably tower congestion.