Anyway, we've been hooked up, and definitely have a solid ADSL2 connection to our local cabinet. Almost everything that uses Internet works, except for browsing the web. That said, some particular websites still work for some reason.
Stuff that works: Skype, Xbox Live, downloading/updating apps on iPhones/iPads, downloading within iTunes, YouTube (on mobile and browser), Facebook (usually), anything Google (googling's fine, same with Gmail, and Drive).
Stuff that doesn't work: most web pages. When on the phone with Telecom the ones we were continually testing and troubleshooting were vimeo.com, speedtest.net, and chainreactioncycles.com. These were confirmed not to load with 2 laptops, an iPhone, and a iPad, so I guess it's not particular device settings.
When it is working, it's fast. Downloads/updates were speedy. The Speedtest.net app works, and was getting ~15mbps down, which is pretty sweet compared to the ~3mbps we were getting with Orcon connected to the exchange.
Telecom were pretty stumped. Their base support elevated it to some other guy, who I spent ages with troubleshooting. In the end he was stumped and got me to send them a copy of the results of various tracert and ping commands. Apparently it's been handed to somewhere else at Telecom to have a look at.
Apparently they'll get back to us in 5 working day (if they can even find a solution...), which sucks, so I thought I'd post something here and see if anyone could help. If you need any info or settings or whatever please fire away and I'll be onto it asap. Thanks!