Rated 4 out of 5 stars
A good addon. Please consider adding some of the following features
1. Automatically select(to delete) duplicate bookmarks by date added i.e delete only the older version or delete only the newer versions.
2. Add the deleted duplicate bookmarks to a recycle bin maintained within the addon. This recycle bin will automatically empty after x days if the user never chooses to restore any bookmark.
This feature will make users more confident in BDD, and more people will be likely to use it and experiment with it.
3. A Link-checker to detect links that are now broken, and give the user the chance to delete all broken links, or to move them into a folder called "Broken Links"
4. The ability to backup bookmarks automatically before deleting them.