Hard to tell since Zelda U has had bits here and there while Horizon has had a few trailers already. Hopefully, both are successful.

Horizon appears promising and looks great, on the technical side and the art side. Zelda U has a mixture of Journey, Wind Waker, Skyward Sword, and other games that utilizes some sort of cell-shaded art-style. Zelda U looks great as well for what little has been shown. When it comes to Meta, I trust the Zelda team more since they have been consistent. Plus, its Zelda with an open world, something the team wanted to revisit and expand upon with influences from the original Legend of Zelda and the Wind Waker. As for Horizon, Guerrilla Games appears that they want to take the next step in their game development, especially after the somewhat disappointing reception of Shadow Fall. I would have to play the games myself to really make a good judgment.

I don't know about sales since first-party games on PS4 do not tend to sell as well as first-party games on Wii U for some reason, despite the tremendous gap in the differences between their respective install bases. I mean, Killzone Shadow Fall and Bloodborne sold over 2 million while Mario Kart 8 is close (or at) 6 million, Smash 4 is around 4 million (despite sharing sales with its 3DS counterpart), and Splatoon (a new IP like Bloodborne) is one of the pleasant surprises this year as it appears to close the year selling around 3 million and appears to continue selling well in Japan and US. Will Horizon (a new IP) break through and sell well? It's possible due to the huge install base. But that's all I can go by. On the other hand, I cannot underestimate Zelda's sales potential, even on Wii U. It could sell around 2 million or around 4-5 million.

As for the techincal aspects, Horizon is showing the power of PS4, which is what is expected now since the developers have gotten used to the hardware. So, I am not surprised that the game is far more advanced in graphical power. Zelda Wii U is more into aesthetics, as many have mentioned already. So on a techincal level, you cannot really argue for Zelda U besides aesthetics as this is more subjective.

I'll say that horizon will easily win on sales while zelda will have a high metascore. Zelda will get a glowing review from just about any reviewer.

Not sure if this thread is a joke but lets look at somethings here.

GG haven't made a good game in ages, Horizon looks good (so did Killzone SF) and has a good idea however GG games end up bland and very repetitive for all the wrong reasons.

Zelda on the other hand has rarely made a bad game when Nintendo is behind it. The DS version even won GOTY in 2013.

I am looking forward to playing Horizon but there is no rivalry between this and Zelda.

Apart from visuals, Zelda will take the cake with a very positive opinion from me.

Big difference between the two is that GG will be spending most of there time on the graphics where as Nintendo will be spending it on what really counts. History has proven this between the two companies.

They don't look like very comparable titles, what they have in common? An open world, arrows .... that's it.

I don't even know what you are saying here. You'll need to elaborate.

Simple question, when you played OoT?

Because definitely you can't have some impresions about OoT if you played it in 1998. or in 2015. (but even in 2015 its very good game).

What are we counting as "ages" because Killzone 3 was in 2011 and had a metascore of 84 which is good in my book.  If that's ages then the console Zelda team haven't made an original console game in the same amount of time.  If we're counting handheld games then the Zelda team just released a title with a meta of 73, which is fairly similar to Killzone SF's 74. 

I don't mind the idea that Zelda as a franchise reviews much better (I think that's obvious to most informed people) but this idea that GG is in a huge slump because of one game that got a 73 could just as easily apply to the Zelda team (assuming it's all one team and not divided in some known way) who just put out a spinoff with a metacritic just as low as GG's. 

Only difference is that Killzone SF is main home console game, not spin off and handheld game. Zelda U is 3D home console game, not fast spinoff handheld game. So I really don't see how you can compare fast spinoff handheld Zelda game metascore with metascore of main 3D home console Zelda games. Fact is that Skyward Sword is home console 3D Zelda game with lowest metascore of 93, while first Killzone have metascore of 70 and last has metascore of 73, that's a pretty huge difference.

zelda will probably win metacritic. gameplay is inversely proportional to graphics on these sorts of comparisons.

Zelda has a big bonus in reviews. There are many reviewers who will simply ignore flaws, just because it says Zelda on the box. Seriously. Horizon has no chance in hell when it comes to metascore.

Talking about sales, Horizon should win very clearly. Zelda games never were big sellers like Mario Kart anyway and the install base of Wii U is just so unbelievably tiny compared to PS4.