Assuming client compatibility, is there any situation where CSS box-shadow is preferable to filter: drop-shadow.
From the article it seems
There is only one difference between box-shadow and filter: drop-shadow. With box-shadow you can use inset shadows, but you can't do it with filter: drop-shadow. All depended on you. Check this example.
Why is better to use box-shadow insted of filter: drop-shadow?
Also, there is one example with image where is better to use filter: drop-shadow. The first one has rectangle shadow, but the other one has shadow which follow the edge of image.
Problem is that there is limited browser support for filter at the moment with box-shadow being much more supported.