The idea is great, but there is some problems with it.
Firefox has two different mechanisms for data isolation:
1. Different Firefox profiles
2. Containers that can be used within the same profile.
+ Additionaly we can use different OS user profiles.

It would be better to be able to open different tabs or windows within different Firefox profiles or OS profiles.

It works pretty well, but the "Always open this tab in new container" is glitchy
One of my tabs just wont open right now. And it's very annoying when I need to open in another container and there's nothing in settings where I can either remove that property or change it.
So I would advise steering clear of that feature.

Would like to have the ability to switch between tabs opened in each container (especially with a keyboard shortcut), would also be great to use as the foundation for tab grouping for open bookmarks.

Let me know if either of these exist if I'm missing them!

Il y a des problèmes de connexion lorsqu'on connecte 2 comptes (gmail, par ex.) dans deux containers différents, c'est assez laborieux et ne fonctionne pas toujours.

It lacks the option to input manually an site into a container so one doesn't have to first open the site and then make it into the container.

I love you! I support your work (give money) I sign all the petitions , I wish I could do more but I am a techno peasant and worst after I retired! and the pandemic

I think the only thing it needs to be perfect it's some new icons

Очень круто! Полезно если есть различные аккаунты... Так же жду поддержки вашего VPN в России... Поэтому пока 4...

Good concept. I had to remove a star because:
1. one cannot clear data of a single container without destroying it;
2. it doesn't group tabs by container;
3. limited personalization options (8 colors and 13 icons, really?).

Muito bom! Uma sugestão seria adicionar senhas aos containers! Compartilho meu computador em casa, então outros acabam tendo acesso a whatsapp, e-mail e outros! Com senha, cada um usa seu container, sem necessidade de refazer login e sem o risco de alguém enviar mensagem se passando por você!

How to turn off always open as this?

TODO:
add grouping multiple tabs into one container in the tabbar ;)
Besides that its looks useful

Sans savoir comment évaluer l'efficacité de cette extension, si elle fait ce qu'elle promet, alors j'ens suis très content.