Right now it's early access for this smart, tactically inclined company and they have tossed a smorgasbord of options for the player to do into the game that allows for almost endless choices/approaches. Lots of it is not yet balanced to the point that it will be.
As Larian watches what we choose to do, and how it all works within the D&D ruleset, they will make changes to improve balance, tighten up rules to make it harder to cheese certain things, improve AI to allow fairer contests, and do away with endless camping and other things that make things overly easy.
Hopefully, they will add iron-person modes and allow for various choices in how one chooses to approach the game.
The bones of the game are fantastic, in my opinion, with balancing and tweaking of what now exists, I can see BGIII becoming a platform for endless fun in a wonderfully exciting D&D structure designed to handle endless possibilities. As much as a game system for future modules as it is a stand alone game.
The most obvious good thing Larian brings to the table fall into the category of tactics and strategy. Players who do have difficulties with the game seem to generally be used to the "charge and kill" sort of approach. BGIII absolutely demands advanced planning and organization. The game rewards the player who gets his archer/mages on high ground and sets themselves into position before the fight, and who finds a way to use the lay of the ground and it's accouterments like barrels of oil, water, etc. Replay from a save is looked upon by Larian as "going to happen" to all players. No one marches through this game successfully without a replay or having watched someone else do it. This is meant to be a part of the challenge, and a part of the game's enjoyment.
That is just part of how the game functions, rather than being a flaw. A player becomes more careful, they learn to recon new areas. One tends to husband their life more carefully, and treat the game world more like the real world as far as dealing with natural forces, once they get badly lacquered once or thrice.
It's all rather splendid.
If Larian currently has a weakness, judging from it's past games, it has to do with the abstractions of "living" and "travel" in a world. They seem to be attempting to address this with their new "camp" feature, which I really love. However, we are seeing only the initial bits of this system, and I am hoping it becomes more robust, and much more fleshed out down the road. They need to bring the robust feeling of realism we find in combat, to the place you hang your hat at the end of the day.
Obviously, they are attempting to do just that.
All of this. Great post.