I use it every day, I cannot surf without this extension anymore!

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So far so good. Nicely done Mozillians :-)

Одно из самых полезнейших дополнений. Очень удобно для использования одних и тех же сайтов из одного окна.

Cette extension est un compromis parfait entre la sécurité absolue (1 onglet=1 session) et la performance (n onglets = 1 session). Je sépare ainsi mes onglets par groupes: "Personnel", "Professionnel", "Finance", "Transactions", "Google", "Facebook" et "Suspect". Cela me permet, par exemple, de rester connecté à mon compte Google sans rouvrir automatiquement la connexion à chaque redémarrage. Un module indispensable pour moi!

so much better than the Chrome's multiple people feature. Thanks Firefox.

Najlepszy!

Thank you for this extension! This extension helps me not to delete cookies and site data when the browser is closed. Though I think there are two points to improve:
1. When a new site is opened, the extension could recommend a container for this site. Will save some time instead of doing things on my own.
2. Be able to delete all the site data only from the "main" space (when no container is in place) when a browser is closed. At the moment, "Delete cookies and site data when Firefox Developer Edition is closed" flag is applied not only on the "main" space, but also drops the data from the containers (which doesn't seem correct to me).

This is a nice addon for multi tasking with 3 or 4 Youtube accounts