Can you give certain/most traffic going to your Xbox priority? Yes. Can you easily control the speed of connection to others users on the network? Not quite. Your traffic would get priority, but you can't place hard caps. You can't go 1Mb for him, 15Mb for you. If you get fancy with your QoS rules, you can get similar results, but not quite the same, and it can get complicated sometimes. Just a heads up.