So basically what I want to know is, if it's better to use in-game settings or the Nvidia control panel settings when adjusting the graphics for games like World of Warcraft? Which one would give me better picture quality without much of a performance lost?
Also, should I have v-sync and triple buffering on in games or turn it off? I'm using the Nvidia GTX 670 FTW.
The Nvidia Control Panel is pretty much a more advanced setting for colors. In-game settings don't give you much, other than detail settings on how shiny, how bright the game look, how smooth it looks and resolution levels.
If you don't like screen tearing
It happens when your monitor and video card is out of sync. You can turn on V-sync, also turning on triple buffering will help the card to prepare frames for video output.
It depends. If you can get the settings you want from the in-game settings, then use those. If you want to enhance or override the in-game settings, then use the Nv Control Panel. There are also several settings in the Nv Control Panel that generally are rarely available in the in-game settings, i.e. Transparency Supersampling, Ambient Occlusion, Texture Filtering levels, Number of frames to render ahead, etc.