A problem I ran into with Views involved implementing an exposed filter in a block that acted like a search. It was easy enough to filter a list of users based on a specific field. In my case, this field was just a taxonomy term reference to a vocabulary. Out of the box, the filter definitely worked if you knew the exact name of the term you were looking for. It even provided an autocomplete to help you out here. However, Views only provided a limited number of operations for these filters.