Does QOS in cheap routers really works?

It will work, however you are most likely going to run in to a different problem. On my comcast connection, if I start downloading a fedora ISO using azureus on bittorrent, all my other traffic slows down. Doesn't matter if it is my work comcast connection or home one. Different routers at both places with business class qos at one and linksys at home. All other traffic slows to a crawl. It isn't something you can solve with QOS, it is your ISP injecting delay into your traffic. http://www.eff.org/wp/packet-forge [...] ast-affair

My buddies down the hall at work run networks around college campuses in apartment buildings. They use traffic shapers that do the same thing. Once they start detecting lots of p2p they inject a 250ms delay and crank the bandwith down. It is all automated crap. The only solutions are things like don't run p2p when you are using the net for anything else. Or find a different ISP or get 2 internet connections.