I prefer the rotating camera myself, gives you more freedom to choose what you want to see and also you can place more interactable objects, secret passages, hidden treasures, puzzles, etc.
Yes, definitely there are things you can do in 3D map that you can't in 2D. And while I disliked move to 3d in some of the older RPGs, Larian's games (and from what I played of Solasta demo) make a good use of 3D maps fully justifying the inconvenience of navigating a 3d envoroment.
