good reason why many subscribers would be opting for the cheap tier, cause they'll never get the speed of the expensive ones, and they don't want to have to chase refunds etc...
could be my shitty understanding of the nbn connection model, but i see 4 outcomes;
1 RSPs forced to provision more capacity per subscriber (if capacity exists)
2 carriers dodge the issue by changing plans and advertising to qualitative (high - med - low) tiers rather than quantitative (100, 50, 25mbps) tiers
3 nbn technology changes to legitimately offer subscribers >25/50/100mbps of throughput as advertised
4 nothing changes in spite of ACCC complaints because aussies are too complacent to bother chasing a solution.
got buckley's chance of no. 3, because nbn has settled on the cheaper MTM ostensibly because the 'fancy network' was voted out with the 'fancy network' government.
my money's on no. 4