I can't speak for your experience with TPG, but a lot of users I know on TPG hate the fact that they have "unlimited downloads" but in reality get limited bandwidth due to an oversold service.

I decided I prefer a limited plan where I know what service level (particularly latency and throughput) I can expect. For instance, plans with Adam and Internode are not that much more than a TPG plan for more usage than I'll forseeably use (I get 500gb a month or so at 20mbps + VOIP for $100), but the difference in gaming latency and actual speeds are both considerably more stable and faster than friends on TPG.