I find array formula offer a nice way to run complicated operations in a condensed form. For example, one typical application is to filter one or more values from one or more (sparse) cell ranges with the following advantages:
- the spreadsheet is self-sufficient and not altered/manipulated/re-elaborated in any way (see pivot tables)
- there is no need for dummy ranges (columns, rows or both)
Conditional formatting can use formula but it seems that it doesn’t support array formula. From my point of view, this means that while array formula allow us to achieve the results said before, if we wanted to show them in a graceful style at the same time, they would let us down. As an example: the filtering job mentioned above may happen dynamically within a large table whose values are variable according to some input parameter(s) and it would be nice to outline the filter result(s) of an array formula through an eye-catching style.