It has a terrible add-on system and you need to have almost every source game ever to join a server without seeing error models everywhere.
What the forget are you talking about? The add-on system is extremely easy. If the file you're downloading is in add-on format (the main folder has a info.txt in it) you just place the folder into add-ons.
And, you need almost
every Source game to join a server without error models everywhere? I doubt that. Most servers only use Half-Life 2 and CSS content.
Sometimes Team Fortress 2. If you have those two/three, you should download Wire and Phoenix Storms Model Pack from SVN and you're good to go.