Also, you need to limit your upload/download to lower bandwidths, otherwise your current setup has virtually no effect.
I pay for 6mbit/768kbit ADSL, but my real-world upload is ~666kbit. For proper QoS (so you can control latencies by avoiding any buffering at the ISP), you need to limit your upload to something below your real-world upload. I use 600kbit, in my case.
I know it is unfortunate, but to properly employ QoS, you will need to do some more research. I had to… I have been crashing down this rabbit-hole for months. :)
Here is a good introduction, in my opinion.
http://www.linksysinfo.org/index.php?threads/qos-tutorial.68795/