Dear Jason
This is largely because upgrades are now done sparingly because of NBN
Your speed issues are because of the movie download services.
I gave up on ADSL and went wireless, even though in an inner suburb.
Thus I have had crashes thanks to Telstra's lack of network redundancy, but when the network actuallyworks,I get 12 to 30 mb/s
Below is a link to some trouble-shooting you chould do anyway