[baruch]

I use a similar tool (pwdhash) and the benefit is not that it's a single password but a single root password. I need only a few changes and very little to remember for most sites and still get a unique password per site.

My bank requires me to change the password every 3 months or so and I only need to change on digit in what I remember and they see a whole new password.

It's a great benefit to me and to overall security.

How secure is it overall? Somewhat more secure than just using a single password for all sites and better trust compared to using a cloud based password storage.