"Oh here's some info I got from MS regarding QOS.--
QoS reserves a portion of your bandwidth to allot to high priority services or
machines. You are correct that if you exaggerate your bandwidth you will see
better results for a single machine, but the router will assume you have more
bandwidth than you actually have, so if and when you do saturate your bandwidth
it will not realize that it needs to be prioritizing particular services.
So while you will lose about 10% of your top end bandwidth in tests from single
machines, the bandwidth is not actually gone. It's just reserved for when you,
or more accurately a machine on your network, really needs it because youre
close to using all your available bandwidth.
I know I saw that before when using the DIR-825.
If I remember correctly I also saw it on DDwrt QOS setup.
Though testing and research it seems as though the same rule applies to SB."