I'm a senior software developer with experience in developing communications protocols and networking software. I haven't been able to set up QoS properly ever, especially in a way that addresses all my needs. Expecting end users to do it is way beyond the realm of possibility IMHO.

It is a huge pain in the ass to get it working right I will admit. Took me hours of reading docs and tweaking parameters. I'm still not sure I understand all of it, but I managed to get it working such that it at least meets my needs.