OK depending on your download speeds I would highly recommend you enable QOS, the default rules should be sufficient for you to at least gain from them - particularly with gaming/streaming. Very easy to do, in the web management->Firewall ->QOS Download-> Tick Enable QOS. In total Download badwidth put your speed of connection and enable active congestion. That way it will set the best speed for QOS to work. On the Upload I can't remember if there are default rules, if there are then enable QOS Upload and set the connection speed as recommended on the page.
Looking forward I create classes based on family members (4 in the family) then allocated ips to the family and then split it 20% between each of us (20% catch all). If say 2 members are on this means they still split 50:50 so nice and fair and it only kicks in if it needs to, it is a very nice system. But the default should mean the line speed remains a better experience for all as a start.
If your connection <10mb I would say it was a must to set this, over your call - its a major feature of Gargoyle so seems a shame not to take advantage of it. Over 20mb you'll see a degradation in performance due to QOS - doesn't kill the line but it will reduce download speeds.
I love my router, still need to update to the latest but it just works!