I get wildly varying service on my MTN/Afrihost connection. Like < 10k (wouldn't even load the speedtest.net page) some days, and 5+ Mb (good for streaming video) others. The modem (the free Huawei from Afrihost) is in the same position in the house each time. There are also some spots in CT (one in particular on upper campus at UCT) where there has never been any signal, but in other places there is this variation.
I think I've seen that the modem is getting 2G signal when the speed is low, so I thought that finding a way to set it to connect to 3G only might improve that, as I've heard that the stronger 2G which phones and other devices will by default choose is still worse than the weaker 3G signal in the same spot. Unfortunately the setting for this appears to have been locked down.
On the other hand I thought I might be the victim of throttling, but I remember on the first of this month the modem was basically unusable, while tonight it was giving me 6Mb/s. I would expect any throttling measures to be reset at the start of the month, so presumably not the issue on the 1st?