Weinberger hates QoS

Joho the Blog: Quality of Service

First, QoS is impractical.
Second, QoS is the wrong solution.
Third. QoS violates the principle of the Internet's architecture.

David Weinberger ruminates effectively on why "Quality of Service" is essentially FUD (fear, uncertainty, doubt) that the phone companies use to confuse customers. It's important to understand that the phone companies want to confuse you and make you buy stuff you don't need. So ignore this QoS stuff whenever you hear it- or at least investigate it carefully.