I haven't found a QoS/shaping scheme that works adequately with DD-WRT, so I just shut the open SSID down.
Additionally, I believe that in the next 5-7 years, the US broadband ISP model will move to a metered bandwidth model, similar to what US mobile carriers are doing now. Just wait.
They'll claim its due to torrenters or some such nonsense, but the real reason will be to extract more profit from their customers. So, I think the whole "open and free" Internet thing will be a moot point in the next decade.