Very buggy and misses important features.
Firstly: If you open a page in the incorrect container there is no way to easily reopen the page in a different container.
Always opening a page in a specific container is an option that is only presented when you have already opened the page in that specific container.
Even after asigning a page to a specific container, if for example you open such a page from a different container you will be presented with an interface to pick whether you want to open in default container or the current one. There is a "do not ask again" option but it doesn't function at all. You are always asked.
There is no administration page, no settings, no nothing. The only "option" is to remember the assigned container after you have already opened the page in the container, and, like I said, that feature DOESN't work well.
Containers also break some functionality. If you have facebook in container A and want to use facebook for login on a site on container B, this will not work.
This addon had the pottential to be a great feature but it's awfully implemented.

Très utile pour séparer différentes activités (notamment bancaires et commerciales) du reste de la navigation. D'autant plus que le paramétrage permet d'ouvrir systématiquement certains sites dans un container particulier

Best thing ever :)

Works as advertised, I can separate accounts with the containers with ease.

I hope this add-on can filter by wildcard, e.g. url like *.google.com.

This feature is sooo useful, especially with sites where you have multiple accounts. Or you don't want one site to leak to another! Or you visit, no soo safe for work sites!

This add-on is nearly essential. It safeguards my privacy, and it also keeps me organized. It's one of the first add-ons I download whenever I install firefox anywhere.

Handy for banking, keeping pesky trackers at bay, and using multiple twitter accounts.

Bueno, pero me gustaría poder enlazar los contenedores con los marcadores.

useless since it cannot sync accross multiple computers...
also it is not possible to define standards (eg. amazon.de --> always "shopping", etc.)

Love it.

works as advertised

This is so useful to me. It allows me to separate my personal life and school life. One time, I showed a Youtube video through Gmail at a meeting. Afterwards, a bunch of anime girls showed up in the recommended tile thing afterwards (it was because I listened to a lot of nightcore at the time, but it was still embarrassing). If you ever worry about something weird showing up on your computer during a presentation, or really any time you have to share your screen, use containers!

It's really helpful for signing into multiple accounts (for example, I have 4 Gmail accounts for school, work, personal means, and an organisation I help run. I don't want to be signed into my organisation's email all the time; I share it with 3 other people, and I'm only temporarily in charge of it. I don't want to have it hanging around, signed in all the time).

Génial pour laisser FB hors de ma navigation normale tout en le consultant régulièrement. Aussi, c'est parfait pour ouvrir plusieurs comptes du même média social en même temps. J'adore.

Nutzlos, da erstellte Container und automatische Regeln nicht mit über Firefox Sync abgeglichen werden. Auf jedem gerät die Container neu einzurichten ist dann auch nicht mehr einfacher, als mehrere Profile zu erstellen.

Just installed. Looks great as it exactly serves my need. And it shouldn't be too taxing on the CPU either! May be Firefox should add this as a native feature instead of an add-on, in future.

Edit: Would be awesome if you could add a way to rearrange the containers.