I've played barely 15 minutes of it, but I've watched someone I know play it for a bit.
1. The world is big, there's a lot of neat puzzles hidden within the world and most of the time it feels meaningful to explore. There's a lot of that "nintendo polish" that comes through with things being cleverly placed to keep you moving.
2. So far, weapon durability sucks. I've had to change weapons up to four times in a fight. I'm sure this gets better, but I still don't enjoy it.
3. I like that a lot of people tell you directions or give you vague hints of where to go rather than always using map markers. There are map markers, but having quests where you have to find stuff based on a picture and a clue are really fun to me.
4. That said, early previews of open world games are always deceiving. There's always a general sense of wonder and awe at scale the scale and finding new things that defines your first few hours with an open world game but his feeling rarely lasts, and what separates the good games from the bad ones is often how compelling the core elements are longer into the game. Game journalists are absolute suckers for open world games for this exact reason, and it's why we have such differing opinions a month after these games come out.
I have questions about how the game will sustain itself: There haven't really been any new items past the ones you get very early on, and I don't think you'll get many new ones. This isn't a requisite of a good Zelda game, but as someone who has always liked item progression, it's potentially worrying.
I have a strong feeling this game is going to be extremely divisive. Maybe not at launch, but a few months out I think you'll have two distinct camps. If you really like open world games like Far Cry or even Xenoblade X and gain satisfaction in exploration over a linear story and progression, you'll be pretty happy. But if you get bored by those types of games easily, nothing I've seen in Zelda (so far) makes me think that this will be the game to cure that. Personally, I like that it's doing new things, but I also think it's going to turn off a lot of people over the long term. It depends on how that back half goes.