It's hard to give a review for this, because the effect can be hard to see. However, being able to separate different websites into different containers is really useful for when I'm multi-tasking and trying to use multiple accounts at one time.

Also, I think I've noticed less scarily intrusive and stalking ads after separating the accounts and cookies into different containers.

Very convenient

Feature request: Make Cookie AutoDelete obsolete somehow

A great and incredibly useful feature I use every single day. This is what true browser innovation looks like. Great work Mozilla!

stream super freaky girl by nicki minaj

This feature is so elementally useful, I am surprised that I have to add it as an extension. It seems like it should be a default feature. It is also one of the primary reasons I exclusively use Firefox. For a while I was happy to use Chrome exclusively because it provided what I needed and the synchronization or backup of each instance was very helpful. Since that doesn't cross web browsers, I only switched because Firefox, lately performs better and has this feature to increase my security, privacy, and account management ability. It doesn't take extra time to deal with these issues because I just have a few pinned tabs with the right container in them. It's awesome.