samgab: Well, my plan switches over to the "unlimited" plan starting tomorrow after midnight.
I'll be very interestedly keeping a close eye on browsing, downloading, and video streaming (youtube) speeds.

I'm in a place (Grey Lynn) where I'm at the very edge of an area which is still serviced by the Ponsonby exchange, and not a cabinet. As a result, we're getting noise injection from all of the nearby cabinets, and we're not in a cabinetised area, but not quite close enough to the exchange to get good speeds from there. So we're in a poor speed area anyway, in terms of SINAD/SNR/ physical connection speed.
We make do, we get just above the perceived cutoff point for socalled "broadband".... just over 10Mbps.
But I find that if I do a speed test to a local speed test site, the speeds are usually just over 10Mbps, but if I try the same to an international site, the speeds are more like 2 or 3 Mbps, and very jittery.
Youtube and other video streaming is a bit hit and miss, and can only be streamed in very low definition most of the time.
I am not eligible for the UFB which is rolling out in my street this Month, because I live in a shared block of townhouses which isn't getting the setup installed, and have no say in the matter.

So, I'll be interested to see if we see any change in speeds as of tomorrow with the unlimited plan.

You may be getting a high error rate.  If so you may find you get better performance with EUBA low interleaving setting, or whatever Orcon names the same on their equipment. (18 versus 9 msec latency type thing).

Thanks. I might talk to an Orcon techo to try to tweak the speed a bit.
I just hate having to talk to the entry level phone answering techs about 4 or 5 times before getting to a level tech who actually understands interleaving, EUBA/BUBA, and signal / noise margins etc...
Oh well, I guess I have to go through it all again. I already went through the whole rigmarole at a place I used to live at, and after frustratedly talking to the phone answerers who don't have any technical knowledge several times, eventually I got escalated to someone who could actually make some changes to the settings behind the scene and our speed at that place went from ~5Mbps to ~20Mbps.
But that was in the early days of cabinets, and they didn't have Orcon equipment in the nearest cabinet at that time, they had to switch us to Choruses DSLAM at their cost. (IIRC Duncan (?) put me onto someone who could help, via this forum.)
The situation where I am now is a little different, and I'm not expecting to get much improvement whilst still on DSL due to our physical distance from the exchange. On the chorus cabinet map you can see cabinet areas all around my street location, but my location is still within the box serviced by an exchange, we're right on the edge of the overlay covered by the exchange.
Ponsonby Exchange area