it does about what you would expect, though there are some serious UX issues I wouldn't have expected from an "official" plug-in. Particularly in regard to the "Always open in this container" feature. You would think after so many complaints/github-issues like #1999 (https://github.com/mozilla/multi-account-containers/issues/1999) about it being hard to undo, they would've done something. Can't in good faith rate this five stars until they fix this, but it's still a decent add-on either way.

Incredible when it comes to privacy and security, but it does have it's quirks. For example you can't add websites to containers by simply typing the url to the website in and you can't add a website and it's sub-domains until you can reach the original website itself (and some websites automatically redirect you to a sign-in subdomain, for example Microsoft)
It is also quite glitchy sometimes. Randomly closing tabs rarely.
It's very good however as websites are limited to their own containers and the switch to containers is pretty seamless.

Excellente extension pour compartimenter les activités entre plusieurs profils sans utiliser plusieurs navigateurs. Très utile, notamment à l'ére du télétravail !

Отличный способ ни использовать кучу браузеров и быть залогиненным на одном сайте под несколькими аккаунтами одновременно.

perfect

Awesome tool! Prevents confusion when using services with multiple IDs.

Entièrement en français aurait été bien.

Désolé, je ne pense pas être aussi stupide qu'un autre, mais votre appli ne fonctionne pas comme vous le dites.
J'ai deux comptes FB et ça ne change rien, je peux pas me connecter simultanément à mes deux comptes, même en regardant la vidéo... rien n'y fait.

An absolute must have.
It allows in the same time to reduce our privacy exposure and ease the use of multiple accounts on the same domain.

An exemple of usage I love is connect to gmail with an account and to youtube musique with another account because it have subscription to it.

PS FOR THE DEVELOPPERS: The only missing feature for this extension is the ability to isolate plugins too.

It is very useful addon! I really love it!