Possibly the best password manager around, but it is not without its (minor) flaws.
First, implement a 'recycling bin' feature so users can recover accidentally deleted entries. This would be greatly improve usability, so users do not have to rely on a backup (if they even made one) to recover their lost entries.
Second, implementing most, if not all, essential settings (such as settings concerning account security) within the various apps would be nice to have, rather than redirecting to the web vault every time a user wants to change these settings from said apps.
Lastly, there seems to be a problem with the Firefox extension for Windows 8.1, where the setting 'Unlock with PIN' does not work. This results in having the user to enter their master password to unlock their vault, even if they had selected said option previously (and unchecked 'Lock with master password on browser restart').
Please consider addressing these flaws as it would definitely be a much better experience for all users.