For starters I would like to mention that we have had this problem for a very long time, I've just being getting more and more fed up with it recently.
We're currently paying for 6-8 Mbits of broadband, measured on a server only 15 miles from here we get about 4 Mbits down and 0.2 Mbits up. When downloading something from steam for example, we get about 500 kb/s, doesn't matter how many people are surfing at once, I can be alone trying to download, still hardly ever passes 500 kb/s. Now I've been looking around in the QoS, googling my issue for answers, and no one seems to have the same problem.
I did try to give Age of Conan priority when downloading a few patches, before setting the QoS I was downloading at 520 kb/s, after setting it to the highest priority (from normal), it went down to 506 kb/s, the drop is obviously not because of the QoS, considering that the priority when from normal to highest, so there's the proof of how little QoS helps me. Please note that no other units were connected to the router during this test.
A friend of mine has the same ISP, paying for the same connection (6-8 Mbits) but has a different router and gets a little higher results measured on the same server as me (he gets about 5 down and 1 up) . The wierdest part is that he's able to go up to ~5 Mb/s on downloads, that's 10 times higher than me; could anyone possibly explain to me why I'm limited to ~500 kb/s?