Tristan, I can't help but wonder if you used a speedtest server in the TCL network, such as (worst case for cable, auckland.speedtest.telstraclear.co.nz, as opposed to some other speedtest server on a different providers network, across goodness only knows what sized network link, whether you'd get something useful in terms of your actual access network speed.
I've just run a test to the auckland speedtest server, at peak hours and got the following.
Likewise, just tried a test to Telstra VIctoria and got this.
So not unacceptable results, even internationally.
if you chose (through lack of knowledge or general sheeple behaviour of) doing the same thing as everyone else and not thinking about what you really want to test, then you risk getting crap info that just proves that not every provider or their mother's second Auntie's provider has a mnimum of 100Mb of uncontested bandwidth available for random speedtests.