Well if nVidia was the one that paid for the AA optimizations to be put in the game, I see no problem with them limitting them to nVidia hardware also. For all we know, if nVidia didn't put the money in to implement the AA optimizations, we would never have seen them in the game, so why should ATi benefit from that? It might not be a case of nVidia or the game developers removing a feature, but instead a case of nVidia paying to have the feature added in the first place. These could have been performance optimizations that nVidia entirely paid for, the whole purpose of TWIMTBP program, so why should then enable them for ATi? Or a completely different reasoning: It could be that having it enabled with ATi cards causes problems in the retail game(remember they only tested this on the demo). For all we know, something with the way ATi cards handles AA causes the game to crash or be extremely buggy with the optimized AA enabled. Maybe a certain part of the game is completely unplayable on ATi cards with the feature enabled, so the developers(nothing to do with nVidia at all) just gave up trying to fix it, and simply disabled the feature on ATi cards as a quick fix to get the game shipped. They now have more time to work on a patch to make it work. It wouldn't be the first time we've seen games have problems with one manufacturer, but not the other, due to certain visual elements conflicting with the current drivers. Either way, I highly doubt nVidia caused a feature that was already in the game to be disabled. How do you know this?