I like that it is easy to use, has great functionality for finding emails within large organizations (especially if you have an account with them).
It can be difficult sometimes when searching through lists or contacts because there are so many people who share similar names but different spellings which makes filtering out results more complicated than necessary. Sometimes its hard to find exactly what we're looking for as well since some searches don't return all possible search items. However, this isn't always their fault - just due to how big our organization gets! This software helps us keep track of everyone's contact information without having multiple excel sheets or spreadsheets floating around everywhere.