Arc also allows you to large-scale organization of tabs with 'spaces'. I have been using Arc (including now) for a few months and find it provides much more efficient organization than Chrome, Safari and Firefox -- however, I have not attempted to use extensions for navigation/organization improvements as you have.
Spaces sound somewhat similar to "panels" in Sidebery for Firefox, they can be used to split workspaces, e.g. for different projects/clients. You can make each panel use a different container, which is helpful to be logged in with different users on the same websites. You can also "unload" panels easily to save RAM and to ignore them until the next time you work on them.
