It's OK and is enough to make me feel I can switch from Chrome's easy multi-profile support. But the containers add-on does not appear to sync settings via Firefox account, so that is a big pain. It also does not appear to let you select a default container for new tabs, which is frustrating. That later wish is actually the only setting I can imagine wanting to be able to set differently at home & work, so some care to be taken there. Keep working on it!