I'm one of this user which has multiple profiles for working. And having the multiple profiles running side by side at the same time. For example, I start a version of Aurora along Nightly. I have 3 profiles set-up, and the profiles manager is set in a way that **never starts** the browser without asking which profile to start. Each time, I request a browser to start I get the little panel widget. This is very practical and compact and clearly shows which one I should start.

Shows how it started before at a first launch (no other browser open) https://bugzilla.mozilla.org/attachment.cgi?id=8702159 And how it will look now https://bugzilla.mozilla.org/attachment.cgi?id=8702158 We can see the regression in terms of UX. I would probably have a compact list right at the top left of the viewport, then descriptions or options when hovering or selecting. The new UI doesn't really work. PS: The fact to have about:profiles is a good idea. The way the UI is managed currently is not good.