UPDATE - Functionality added shortly after this review. Now works as seamlessly on Firefox as it does on Chrome

Terrible on Firefox. No option to copy the password for the site you are on, or search for, within the add-on. You must open your vault to the site in need, show password, then select and copy. The Chrome extension has the option to copy username or password direct from the extension. This is handy when you are asked to re-enter the password, but not username, for a site. In Chrome, I can just go to the extension, show matching sites, copy password. Shocked this is not an option with Firefox.