depends on what you want to use the line for.
For me I have a 40M line and never think this is too slow, even with family streaming services etc.
Check the sync on your modem. If that's around 68M, and you can download at 64M, then the line is working ok. for me I would not get worried about the difference in HTTP downloads vs the other type. I now look at how the internet service is performing for the apps I use.
Basically I have stopped using speed tests..