First we would like to give a few tips on configs with mods. One simple way to keep track of the configs you use are to name then for the mods they are used for. You can then either place them in the mod folder with the autoexec.cfg that executes them, or you can place them all in baseq2 and only place the autoexec.cfg in the mod folder to execute the config for that mod. Use whatever system works best for you. I personally keep all of mine in baseq2 and manage them from there.
Many people tell others to set it for brightness.
Many cards these days are not affected by this for game brightness. This section is about what to look for when your config doesn't seem to be working. One of the best ways to test whether or not your config is working is to bind a key to say something in the game. Then go join a game and hit the key you bound it to. If it doesn't work, you know you did not get execution of that config.