I've been with Telkom's LTE since August 2015, and have never had an issue. I primarily play SC2 and D3 online. My latency is maybe 20ms higher internationally, and I don't feel the difference to be honest. Also, I never get disconnected, which was a constant issue for me on ADSL once the rain started falling. Weather has never interfered with my connection, not even once. I game just fine in the middle of an end-of-the-world thunderstorm.
LTE is in no way the same as HSDPA/Sentech/Neotel WiMax in terms if quality. I've tried all those in the past, and they were unusable for me after a month or two due to congestion. I only got LTE because the ADSL in my area was installed just after creation and thus nearly inoperable.
I see people recommending you get a test system first to see how it goes, but did you know that the consumer protection act in SA allows you to return any product in SA within 7 days for a complete refund and contract cancellation? I confirmed this with Telkom before I got the LTE router. I could thus get a brand new system and test it for a week, and return it if not happy with it. Luckily I didn't have to.