This is definitely a useful add-on!
The possibility to restrict certain sites to specific containers is really a plus as compared to the basic containers that come with Firefox. It gives less risk to open a site in a "wrong" container or the default one.
It's also quite cool to know it impairs giant sites (Facebook, Google and others) to track one's online activities. I created a google container by the way.
However, the lack of sync ability for the moment costs one star, though it is foreseen by the developer. I found a temporary workaround that is to sync containers.json and ../browser-extension-data/@testpilot-containers/storage.js (both found in one's Firefox profile) through a sync application (FreeFileSync does it very well, download it from here: https://www.freefilesync.org/)

Really great.

Even better if container preferences were synced between computers.

this addon is truly the finest.

It is a really useful tool to keep your browser organized. It enables the capacity to have more than one email account in the same service (gmail for example).

It would be nice to have a right click menu to open a link in a specific container or change a tab to another container.

i love him

Love the idea and the simplicity of extension! On the other hand the extension lacks 2 must-have features:
1. Sync containers: name, icons and - the most important - assigned sites for each container. Actually this functionality can be implemented by syncing 2 files in profile folder only: containers.json and storage.js (in extensions folder)
2. the option to open a link from containerized website in (a) a no-container tab or (b) in default-container tab
Otherwise is great.
Cheers!

love the simplicity and ability to seperate sites

Very useful, does exactly what it says on the tin very well and boosts my productivity nicely.

Fantastic - keeps your worlds separate where they belong

Un must-have qui devrait être intégré dans le navigateur !
C'est idéal pour isoler les services très curieux, auxquels vous êtes connectés comme Facebook ou Google... Par exemple pour Google, vous pouvez toujours ouvrir YouTube dans un conteneur dédié, où vous êtes connectés, ce qui permet de rester "anonyme" sur les autres services de la firme.
Il ne manque plus que la synchronisation de ses paramètres dans Sync et ce sera parfait.

The best feature Mozilla team can offer on Firefox.
Love it.
Request - Please have containers synched between different FireFox devices.

Great potential! What's frustrating is there is no way (that I know of) to sync the settings of this plug-in. I'd be happy if settings could be imported & exported, but that's not an option. It would also be nice if privacy settings could be configured per container. I typically configure FF to nuke cookies & history upon closing. But now that I can configure some sites to always open in their own container, it would be nice to preserve (and sync) cookies/settings for those specific containers.

Really useful as I sync Firefox between all computers and phones. Helps to keep work and personal life separated.

Really good. Solved my workflow issues instantly.

A must-have, very useful

Works as advertised :-)

This is so useful in a time where people have multiple accounts! The only thing that really needs to be more clear is that it does NOT work with "never remember history", because it took me over an hour to figure out why it didn't work while having all kinds of 5 star reviews!

if you have multiple accounts (work, personal, etc), this is the best add-on for you!

Great