what exactly makes this game more ambitious than other open world games from Rockstar or CD Projekt Red?
First of all, they're going for very different things. I'm talking about gameplay here, and you don't have the gameplay depth and level of interaction shown in those 5 hours of gameplay in the titles you mentioned, not even
remotely close. Which is even more absurd when you think that the gameplay shown was entirely limited to the tutorial area, which is less than 2% of the game. They're basically going for the level of interaction seen in titles like Dishonored, possibly more in depth, and they're applying those concepts (and other new ones) in a giant open world game. That's simply insane. Also saying that Zelda is more ambitious in terms of gameplay compared to other open world titles doesn't mean that said other games are suddendly shit. I spent more than 400 hours in The Witcher 3 and over 200 in X, and they're easily amongst my favorite games ever. I also consider GTA V to be a masterpiece despite having always hated the series in the past (with the exception of Vice City).
Nope, checking again the video, there are big differences between areas. As I edited later, the textures in the snow area for example are way poorer.
Keep in mind that the demo is likely over 1 year old compared to the final game. Not saying that the final game will have Witcher 3 textures, but the game clearly is not finished.
I'm willing to bet that the aliasing will look as in the latest video, not as in the E3 demo on Wii U. Especially with the framerate issues.
Why? The game is using edge smoothing AA like Mario 3D World. The game showed dips in the mid 20s and even sub 20 in the E3 demo,
which were reported by digital foundry. 30fps with dips when shit gets real is more realistic than constant 20fps in a Nintendo game, especially when the latter is due to shitty encoding.