Cable internet was installed on Friday, but it turns out there was an issue with the HFC cable laid in the street. Telstra sent someone out today and replaced the faulty cabling. Works like an absolute charm now. I get right around 30MBps, which is a massive improvement from the 5.3 -> 5.5MBps I was getting on ADSL2+.
Motorola SB5101i modem and D-Link DIR-655 router: