If I have a text field, I can't filter with "is empty". I just have the options "starts with" and "equals". The most time, that I have complete data is on empty fields.
At the moment, I have to create a report, export the report to CSV, do the mass change in the CVS file and import the CSV file and update the content. It would be easier, i I could filter this empty field, mark all and do a mass change. It would help me a lot.