@decryption good question. I have the pre-2000Mbit NTD with multiple Uni-D ports and hit the limit of only being able to have one port connected at 1000Mbit with the rest at 100Mbit max.
My NTD failed in December after ~5 years of solid use and the NBN tech still swapped it for the same model despite the 2000Mbit NTDs being available then.
I'm very tempted to move from a 1000/400 plan to a 2000/500 plan but I'd end up spending way too much replacing my switches and APs with 2.5Gbit variants.
I priced replacing my main 8-port PoE switch at a 4x difference between 2.5Gbit and 1Gbit 😥
@decryption I know the new four port NTDs have a 10Gbit port and three 2.5Gbit ports so at least that's not the bottleneck.
I only learned the limits on the old NTD by going through the sign up process and being told by the second provider they couldn't provision more than 100Mbps unless I downgraded the first service.