I use Chrome profiles heavily, so I am very happy Firefox is exploring this feature. When doing consulting, I like to keep different client activities isolated to their own profile, so I have less things to juggle if they use the same cloud service (AWS, G Suite, Jira, etc).

One limitation I currently see to that workflow (that works better for me in Chrome) is that this appears to all reside under a single Firefox Account which essentially creates master set of data to Sync. I would like to be able to setup Containers to be pegged to different Firefox Accounts (or not at all).