It's aimed at people who don't know the difference between UDP and TCP (and possibly wet string). Yet he recommends they implement their own reliably protocol over UDP, and they avoid TCP because it's better to implement your own QoS?
Why not add obtaining PhD in quantum mechanics just to round it out? It wouldn't alter the odds of pulling it off overly.
The choice you make depends entirely on what sort of game you want to network.
So from this point on, and for the rest of this article series, I’m going to assume you want to network an action game.
You know games like Halo, Battlefield 1942, Quake, Unreal, CounterStrke, Team Fortress and so on.It's definitely not an easy task for beginners, but these days you can pick up his library that implements this stuff.
For people who are not familiar with TCP and UDP, the answer should be to ALWAYS use TCP.
The only exception is some subset of games (FPS, RTS), that this article is exclusively intended for.
Even there, for the average user who just wanna make a test game project, TCP may be easier to use and program around. For simple games (e.g. Connect 4), TCP is a better option either way.