I have been using this for some months now and am very happy. I separate containers by work, client and personal and can continue working on all without having to jump windows or using profiles. I have found this to be more user friendly than profiles being used in other browsers.

Works great for keeping accounts separate. I use it for keeping my home and school accounts separate across services.

I'd love for a future update to include support for syncing containers over Firefox Sync (it's annoying to have to re-create my containers on each device I use).

Also, the current interface for opening a new container tab seems kind of clunky. Having to hold down the "+" button is unintuitive and takes too much time (what can I say, I'm impatient). I'd much prefer having multiple "+" icons next to each other for each tab. Perhaps color each button the same as the corresponding container to make it even more intuitive.

Save a lot of worry and cleaning history betweensites.

This is why I stick with Firefox.

Works as intended. This makes trolling 100% easier. No longer do I need 7 different browsers to accomplish my tasks.

a little suggestion:
if i place the toolbar button beside tabs (or the original new tab button), could it be aligned to the left?

I'm using it since many months now, and it made my life so easy. Don't have to open different browsers for multiple web based emails.

Works as designed.

New Features:
1. Bookmarks by containers - low priority
2. Save settings by containers - like when i apply charting settings on yahoo finance, and open another tab inside same container, those stock chart settings are gone and i have to reapply them.

So cool :)
This allows me to "box" all google websites in its own container and all Amazon websites in another.
Plus, I can have as many containers as I want, in case I want to log into something with different accounts at the same time.

The importance of a browser extension like this can not be overstated. The fact that Mozilla them self maintain it makes me feel warm inside. Much privacy very container!

Usability changes/default selected container type when opening the popup/shortcuts to open container

best add-on ever created

Very useful. I'm using multiple accounts on for the same site and with this extension I don't have to deal with multiple browsers and incognito mode.

This is one of the most amazing feature of Firefox, at work we use the GSuite and Chrome with multiple accounts: this add-on allows me to ditch Chrome entirely.
I am also converting other colleagues to it, little by little.
I am an IT Technician at Salesforce :)