We use it to show related data from several different tables and / or several different views from the same table in one dashboard view (i.e. we have a general dashboard where we want to see, among other things, what projects are due delivering certain required documents, with those due lists defined in different views). The fact that you can limit the number of displayed records and that sorting is independent of the original view makes them doubly useful for our particular scenario. Where I agree with you is that it is not particularly useful as a reporting tool – that is something the Page Designer block is meant to tackle.