LOL. well it's basically just degrees of AA.
as an example. set Nvidia AA to "application controlled", and in your game set AA to 4x or 8x.
Then set your Nvidia AA to Override and 4xQaa or 8x Qaa and the game to NO AA, and you will see that with the QAA, antialiased objects have like a micro blur filter around them, to make them look even more smooth. Then there is also Supersampling and Multisampling. Multisampling gives better performance, while Supersampling AA is just awesome for Image quality
Always found that the quality provided vs the performance drop in AA not really worth it... matter of fact, most of the time AA is hardly noticable which you are in the action.
/me being an AA slut, I do notice it, even during furious firefights or racing![]()
Sometimes people just can't afford the AA, cos of hardware, and the ridiculous res' they run. It's often a matter of choosing low fps over wow-it-looks-so-awesome-oh-crap-I-just-got-shot-but-my-frames-are-so-low issue.
For instance, I can live without AA, but I can't live on low frames. Hurts my eyes, and irritates the #$#$$%^Q#$%#($% out of me.
This is where pc is beter than consoles. PS#, Xbox, Wii, etc never apply AA to there games and end up looking a bit weird. If you don't believe me go look for your self.