Sigh.
Here's my findings after I spent the whole day running between houses, moving routers around, climbing up and down rooftops and painstakingly adjusting the routers' default paddle antennas.
On the router with the 24hr uncapped sim we never achieved anything higher than 500kbps on fast.com. No matter where we placed the router, even on the rooftop of both houses, not once did we get past this speed. Seems to be capped at this speed too. I think its worth mentioning that most of the time we got speeds of about 300kbps, depending on the location of the router.
The best signal stats achieved was RSRP of -62 and SINR of 17.
The surprising thing though is DStv Now works just fine, Netflix also worked but both started to buff when resolution was set to anything higher than 480p. What I did notice last night that both these services worked without buffering at 720p, at the time I didn't think to try a higher resolution or to run a speedtest.
On to the 19hr uncapped sim. Same speed test results, also averaging between 200 and 300kbps and topping out at 500kbps. The same applies for signal stats, identical to what was achieved on the router with the 24hr sim.
DStv Now would occasionaly load the homescreen but not once could we manage to get something to stream. Even after setting default resolution to its lowest, 360p, we still had no luck. Netflix was even worse we couldn't even get the homepage to load. I did manage to get Youtube to work though but it was buffering every 5 seconds.
So the conclusion I came to is that on the 24hr uncapped plan, Rain allows you to stream Netflix and DStv at a capped resolution. Between 6 and 11 you can stream at whatever resolution your connection can handle. Those of us on the 19hr package are screwed. No amount of tweaking will help you, unfortunately. I absolutely could not get Dstv or Netflix to work no matter how strong my signal was. I think Rain throttles all congested towers to a limit of 500kbps, except if you're 24hr uncapped then you get to stream at a capped resolution of 480p, after 6 it goes up to whatever resolution your connection can handle.