I may have blamed Afrihost for no reason for my streaming issues.
So, it was everything except Youtube that was stuttering, but some videos on Youtube as well. Someone here mentioned that some Youtube vids are stored locally, so I guess that it was the cause of that problem, but then I still had the slow streaming.
Seems that somehow, the hotter my router gets, the worse the latency is. Now, it's not horrendous, maybe one or two big hops for a traceroute from here all the way to Europe.
Sunday evening, I was unable to stream the Formula 1 build-up show properly, and I put my hand on my router, as I always do, and it was a little hot - which I thought was normal for heavy usage. Then, I had this glass of water next to me, and I had a silly idea to put this on the top of the router. Few minutes later, the stream stopped stuttering, and no more glitches even til after the race. I felt the router as soon as it started running smoothly, and it was certainly more at a normal temperature, almost the same as room temperature.
I thought this could be coincidental, so I left it on, streamed something else, which was running fine for a period of time. Then I took it off, and within 10 minutes, it became unwatchable.
So, thank you Afrihost for trying to help, and for falsely accusing you of bad service. Although I never thought of something like a too hot router, especially when it's not even extremely hot. I guess some components just need more cooling than others.
Who knows, maybe this helps someone else.
Cheers