I would also like something like the easy user switching that chrome has, since once user would have one set of session tab logins (twitter, fb, google, etc), and another user would have another. firefox -no-remote isn't that smooth of an experience compared to chrome's user switcher.
I can't really speak to Firefox's performance issues though. I feel like they're just as good on rendering and JS speed, but the overall UI doesn't have the same "fast" feel that Chrome does. Chrome has also seemingly gotten slower for me too.
[0] https://addons.mozilla.org/en-US/firefox/addon/multi-account...
The fact that you can't sync container configuration between devices is also a huge pain point, when you have a nontrivial setup.
I still use them, but I accept that I'm going to endure some pain now and then; I can't recommend Firefox containers to people who just want to get work done right now.