uhh. iiNet is not great for usage.
'Node offers far more value for money than iiNet. (you don't need to sign up to their phone services

)
Lets compare the $59 plan (without Phone1 to make it fair)
iiNethome 4 - $59.95 ADSL2+ speeds 7GB + 14GB $59.95
InternodeHome-Extreme-Value
$59.95 Extreme ADSL2+ Speeds 25 Gbyte
So iiNet offers 21GB for $60 and 'Node 25GB for $60. And really, you can only use 7GB of true usage, unless you're US Session trader (lol) or an insomniac, to access the 14GB "offpeak" usage.
And compare iiNet to other ISPs like TPG, it's not really a "big usage" company. Rather, they also concern on bringing a stable and quality connection to the customer unlike tpg lol