But a smaller development team and less development time and budget would indicate Xenoblade X would be more ambitious.

Wind Waker's world isn't even remotely barren. There was a ton of shit to do, even in the GCN version. Neither is Skyward Swords, and I hate that game. SS's whole MO was content density. I'd argue that only TP and OoT's worlds are less alive than what is in XC, and those games are commonly criticized for just that. XC isn't even remotely a good example of an alive world. All you to is fight enemies and pick up items. It may as well be just as barren as TP. The way you fight enemies isn't varied or dynamic, and the way you pick up items isn't varied or dynamic. You walk up to a blue diamond and press a button. You walk up to an enemy and enter a battle phase. The only reason those things become interesting is because of context, which is not ambitious at all.

By contrast, the "barren" world of the Wind Waker ala the great sea is filled with a wide variety of different kinds of isles and islands, navy bases, sunken treasue, ghost ships, giant octos, a tsunami god, watch towers, flying fish, battle ships, submarine dungeons, rafts with enemies, sea charts, a chain of shop ships, and a chartable map. All are interacted with in completely different and dynamic ways.

I love XC, and I'm exited for XCX as well, but let's not make it out to be more than it is. The franchise depends a lot on imagination to make up for what it can't do, which is fine because it does that spectacularly, but it isn't even remotely this benchmark in ambition. It's just big. If Zelda is only like Wind Waker when it comes to it's world, it will already be exponentially more ambitious than XCX is in that department. The horse thing isn't even unique to Zelda U. They are just this game's version of the seagulls in Wind Waker. Nothing spectacular or unheard of.

"How many" doesn't matter. It doesn't matter if their are less races. They'll all likely be better animated. Wind Waker had a completely new line of new races. SS did too outside of the Goron. And Minish Cap. Saying that Zelda recycles races is being willingfully ignorant to like half the franchise. Complaining about the reuse of Hylians in Zelda is like complaining about the reuse of Humans/Moms in XC. It's silly and hypocritical. There's no reason to believe, based on what we've seen so far, that there won't be a completely new line of races once again for Zelda U. At this point, only you are only guessing.

We definitely don't know, but we've seen various examples of what it could be. We've seen bottles in WW, duels in ALBW, and obviously TFH. We know for sure that it's going to be a big aspect, as it was labeled next to exploring dungeons when being labeled by importance. It could be many things, and I see little reason not to use these examples, especially the idea of playing as multiple Links, in speculation of what this could be. Putting them all together makes the whole thing seem very Dark Soulsian/Chalice Dungeon-like. I can easily see something like this being in Zelda U, and that would definitely match the ambition of XCX. Remember, when the game was first revealed, no one could have predicted just how multiplayer driven it was. Zelda U told us before the game was even announced.

And again, quantity doesn't matter. Quality does. XB and XCX only uses crafting to effect dry numerical stats. In Zelda, not only is the process of getting the materials more dynamic thanks to the very nature of the gameplay, but the results of crafting are more dynamic too, effecting the way you interact with enemies as well as the world in a complex and substantial way. SS being the gold standard example of this. Less variety than XCX, but the results were far more meaningful than anything you'll likely craft in XCX.

I doubt that

So you're telling me this

https://www.youtube.com/watch?v=JxPBNYZv1Qg

is anywhere in the same ballpark in population as this

https://www.youtube.com/watch?v=r1MYZbBPCgM

Lol, you're joking I guess?

Then you talk about items in Xenoblade Chronicles, and say all you got to do is press A to pick it up.... But that's the same as going to where the treasure chests are in wind waker and hitting a to pick them up. Same could be said for fighting enemies... Only you don't fight them to pick up items to craft things, you fight them simply to fight them (except for Skyward Sword to a very, very small extent). Saying there is no variety in the way you fight enemies, but what? LoZ offers more enemy fighting variety? Lol, no. There are more ways from trinity attacks, to soul cries, to buff and debuff attacks, to aggro, to party placement on the battlefield. And Xeno X will be FAR more than that.  And crafting weapons in Xeonblade X will also greatly change the way you approach battle. If your defence stats are low and your ranged weapon attack power is high, you will approach a battle completely differently than if your defence stats are high as well as you melee weapon attack power and everything in between. 

Your first post had some great points. This one though...

-I dont see why realistic graphics makes X more ambitious game, Zelda U looks so much better than Xenoblade X.

-Zelda U will probably not have voice acting at all because it not same concept of game.

-We dont know anything about loading screens in Zelda U, but in that gameplay from December we didnt had any loading screen.

-We still  don't know anything about Zelda U online components.

-"See those mountains? You can go there!".

-We still don't know anything about customization of characters.

-Skyward Sword had armor and weapon crafting, so probably Zelda U will have.

Things that Zelda U will have:

-Much more prettier and more interesting world.

-Better gameplay.

-"Better" dungeons.

-Better and more epic Bosses.

Personaly, just fact that Zelda U is first HD, true open world and most ambitious Zelda game ever, makes Zelda U far more ambitious game than any other Nintendo game.

Half opinion, and half speculation. And while you say Zelda will have customization and crafting, will it be anywhere near as deep as Xeno X? Also, getting a cast (and even going as far as finding and bringing in veterans of the series) in to do the voice acting for a game does show more ambition than just text.

Speculation because we still don't know, and opinion based on facts. ;)

But its true that Zelda will no have crafting deep like X and that probably will not have any voice acting or online multiplayer, but that really don't change anything when we comparing this two games.

VA doesn't show more ambition it just shows different approaches and concept, Zelda for most part you're playing around with game mechanics and getting around the world the's not much key dialogue that even warrants VA unlike RPGs.

Applying the Zelda template to an open seamless world is ambitious in itself.

Except for all those things show ambition.

I would completely disagree about the voice actors thing, but you already know that. I would say making Xeno X as big and seemless as it is takes just as much ambition as LoZ. With less of a budget, smaller dev team, and less time to create it.