My understanding of the whole thing is bringing the dslam closer to home by putting it in the cabinet, all Hamilton exchanges have Telecom/Chorus ADSL2+ gear in them so no matter what broadband ISP you use, your router should get an adsl2+ connection to the exchange, this includes all the cabinets as they are being fitted with ADSL2+ gear. Only reason I can see anyone (regardless of ISP) getting an ADSL1 connection would be a really bad line or have locked their router to adsl1.
The issue as I see it is what kind of speed the end user gets from their ISP, e.g say you have a 18mb connection to your cabinet or exchange, but the ISP who is supplying the bandwidth may have limited your throughput bandwidth to 8mb since they are supplying all of it.
I know hamilton will get unbundled exchanges eventually but I think the cabinet roll-out program here will be complete once done so we will have to pray that Sub-Loop Unbundling is sorted so say if your an orcon user then your line will be physically hard wired to their gear.