Midair:
I agree with you there. E.g. Might & Magic X: the environment, buildings etc. look natural, no matter which angle you look at it. So if they had chosen 360° movement like Wizardry everything would still look good - from any angle.
@Easier to implement grid-movement:
Not necessarily. I am not sure that the grid-based implementation is easier and let me explain why:
1) You have a headache defining grid-cell-sizes... because:
2) You must implement how many monsters can occupy a cell e.g. 1 medium monster 1 small monster OR 3 small monsters OR 1 large monster ?
3) - which means you are limited in your freedom to use creatures of different sizes
4) You must implement choppy and weird grid based movement for player and enemies
Opposed to that there are free high quality libraries for Unity (both MMX and Deathfire use this engine) which allow to throw a grid with much finer granularity onto the world. Once you recast this the grid automatically sees which areas are possessed by creatures and which not. A monster will just occupy an approximate amount of these small squares e.g. 20pieces, depending on the radius of the monster. Due to the finer granularity of the grid a smooth curved path can be calculated to the target and the calculation of this path as well as the occupied squares is already integrated into the library (yes, I know that, because I have used it). Now you would just need to check some points within this calculated path, if the radius of the monster still fits through this passage and voila you are done:
Advantages:
1) You don't need to care about monster sizes, or inner subdivisions of a grid cell. Full freedom for artists
2) You can use 360° movement using a common FPS controller for all creatures
3) Monsters can approach you from all sides - no such thing as maze-like movement
- and you could still use turn-based combat. Honestly I don't get why some people repeat over and over again that "grid movement is so much easier".