Back-In-Time's ability to clearly show on one screen what backups are available for a file or folder make the Time Machine much easier to use. Instead of having to grope and guess in Time Machine at where backups of a file might be you get the info all at once on one Back-In-Time screen.

Since I have only used the app for one day I didn't rate quality/stability--actually just stability, the quality seems great--but I have not had any problems during the time that I have used it.