I like the purpose of this add-on, but gave it only 3 stars because it currently fails in its stated purpose to "Keep different kinds of browsing far away from each other ... ". It will automatically open a container when it detects a site assigned to it. However, once in a container, it will open websites in it that are not assigned to any container. I find that it's very easy to forget to manually open a new tab when going to a website not assigned to the container. When in a container and opening a website not assigned to it or another container, a new tab should be opened automatically for the new, unassigned website.