There'll probably be an option to zoom out a bit. The videos seen are all at that zoom level so we can see the nice textures, not the overarching tactical gameplay. But there doesn't seem to be any lack of verticality in the scenery, tactical initiative to hold the high ground, or a huge amount of blocking by obstacles. It's not Ultima 8's jumping puzzles, more like a Barb from D2 going "imma gonna jump *there*". Not necessarily the most realistic thing, but it seems that movement is pretty open on this one.
There also seems to be plenty of little bonuses for use of the environment as well, but not totally enforced ones either. Just stuff you can do, if you want, and that's a thing your character would use if given the option.
I'm actually a bit of a fan of the I-go-U-go turn based system for combat. It lets you chain awesomeness together, and works really well for CRPGs. It allows an aspect of forward planning that's unavailable in individual initiative based systems, but works more fluidly than real-time with pause, giving you more planning/tactics/character-building and options of how to deal with things.
I also like the sound of the real-time, but turn-based when you want it, system for exploration. It allows tonnes of decent set pieces, but also a fluid approach on how things play out. As well as a proper stealth system outside of combat. It's not like you'll never use the save/load system, so even just trying out stuff for funsies is worthwhile.
Hell, just having a save/load system removes a game so far from "proper" DnD that you may as well roll with the changes from there, and assume that they were put in to make a better game, not a worse one, for the players of it. And I am a fan of DnD, from 2nd, all the way to 5e, minus 4th. But it's a computer game. Having a strictly 5e system enforced on a game I'm going to buy would just make it a crappy, boring game when it came to combat, when I'm controlling all the characters, so I'd rather the chain-awesomeness of BG3's one. Makes it more fun, for the power fantasy it is. And I'd rather pay for a good computer game, than for a bad one that stuck to the system it's loosely inspired by (or one that stuck rigidly to its predecessor's formula).
Here's Rock, Paper, Shotgun's little review of the very early demo, and it's honestly looking pretty good on the gameplay options front. With a fair amount of replayability with different character classes, party compositions and tactics used as well:
https://youtu.be/IZ0LJ5BqYrkI'm pretty excited for this one