I've been using the built-in Containers in the Nightly browser since they first became available. Admittedly they are a power-user feature or for those that are vigilant about privacy/tracking.
I recently switched to this extension (over just the builtin version) to get the "Always open in container" feature which is pretty much indispensable due to external apps firing browser links (slack, email).
I wish there was regex/pattern matching support and literally any interface at all to see existing settings. The CookieAutoDelete extension has a great UI for managing cookie regex settings per individual containers - please implement something similar for this extension!

very nice add-on. i managed to log-in multiple accounts and never had to repeat logging in again but i hope we can password protect it so that other users of the computer wont hack the accounts in it.

must to have add-on. it would be even better we can open a new window locked with a container

Feature request: allow for Firefox Sync so multi-account container settings can be synced across multiple computers.

I really like the idea. So far I have only two problem using this add-on: when I open a new container-tab, it will take some time (an unacceptable period of time) before it's ready to work; and this add-on lacks of rich keyboard shortcuts which is something I quite depend on.

Good to have multiple account. Not so good to manage multiple tabs in groups.

Very Good! I use it a lot! Thank you Mozilla!

Good apps

Very easy to use, and does its job perfectly. Would love some more icons, but definitely doesn't take away anything.

Its the best thing from firefox I have used in a while, keep it up guys

I would love to be able to tell this addon to open specific URL:s in specific containers, not just based on the domain name. My use case is handling several different twitter accounts, and based on which account URL I type it would be great to have it open in a pre-determined container.

It lets me do what I want with my multiple accounts without dealing with chrome or much hassle from my part.
I would love it if right clicking new tab opened up options for it or similar, keybindings would also be nice, it currently takes too long to click and hold, and is a little bit awkward.

Love it, just one thing to improve, it would be great if all tabs are synced with the browsers account, in that way we have the same tabs when we change laptop or switch between machines. Thanks!

While the add-on mostly works okay it causes some strange problems. On sites such as pinterest, if I click on a link to open in the same tab, it works fine. If I middle or right-click to open the link in a new tab, the first image or header displays, but the rest of the page is blank with a spinning wheel icon at the bottom, as if it's loading more (which it's not, there is no loading indicator on the tab itself). It does this for every link on every page of pinterest.

With this extension disabled, I get the normal expected behavior: the page is complete on both same and new tabs. I'm only using pinterest as an example, because I know the general layout of the images there. I know when I'm not seeing most of the page. Since I don't know this for most other sites, I don't know what other information on not seeing on those sites when using new tabs with this extension.

Until I know I can open in a new tab without losing information, I won't be using this add-on.

It has helped me separate the browsing history. I will love to have the posibility to move tabs to Containers, or open new link/tab in a specific conatiner. Super nice idea and implementation so far :)

Automatically opens certain websites in secure or private containers. Very easy to use.

I really like this addon, it's a nice intermediate to what I really want: concurrently running sandboxed accounts. Lately, however, it appears to be a bit broken. When I open a link from an email in Google Inbox ("Fun" container), that should end up in a new container (e.g. "Finance"), the new tab closes immediately, and I'm forced to right click to open the new link. This stinks.

When working with multiple Microsoft/Azure accounts for different customers/tennants, I can now stop using In-Private windows all the time and just make sure I access the resources from the right container.

I love the concept! It's private, easy to use, and should be BUILT IN to Firefox! I just wish you could add more icons, each container has it's own individual history, passwords, etc. Also, when I sort the tabs, it moves the new tab button to the left, and I can't change it back, which is annoying. What would be nice is if I didn't have to open a new tab in a container by having to go to the container menu. If it would be right next to the new tab button, where everyone would see it would be awesome. Overall, great!

It does what it's say, and in a smoothly way.
Really useful.

This should in fact be part of Firefox by default! Most useful IMO is the option to automatically assign a default container to a website so the same site will always be opened in this specific container. Good for privacy and separating business from personal sites and such.

Make easy to use multiple accounts

Inestimable ! Pour gérer plusieurs comptes Twitter, c'est indispensable.

Useful for keeping cookies separate. Would be nice to keep add-on's and their data separate too. For example, MetaMask should only be enabled in its own container.