It doesn't matter at all. QoS on your local net will let you prioritize your VoIP over your streaming video, but has zero effect on your throughput if you are constrained by a shared resource upstream of your router.
Some people share their LANs with more disruptive users than others, so QoS on that LAN can be useful. But the article was not clear at all.
Some people share their LANs with more disruptive users than others, so QoS on that LAN can be useful. But the article was not clear at all.