What's so badly b0rk3d about DSLAM rate-limiting and the new QoS implementation that causes latency to jump like that? Anyone know?

If they're dropping the DSL line rate down to plan speed then your bits will take longer to wander to the exchange. It makes quite a significant difference when moving from 8 odd Mbit/s down to 256kbit/s downstream. Can't really take jibes at Telecom for this. If they are taking this approach, then the slower line rates will also mean less RF inteference in the cable binders, which means more robust [albeit slow and piddly] DSL connections. This is how most, if not all, providers work in Australia. Cheers, Jonny.