It would be useful to set criteria when running a duplicate check.  Far too often the duplicates report has less records that are duplicates then it appears.  It is hard to tell what it is thinking or why it determined 2 records were possible duplicates without the same last name or address.  It would be nice if you could run it on first name, first 5 characters of the last, city and state or email.  You could adjust it based on the results.  They way it works now is very frustrating.