It's a simple UI version of Profiles.
The choice of container is no more or no less complicated than the choice of profile for links in external programs (or within Firefox)
The choice of container is no more or no less complicated than the choice of profile for links in external programs (or within Firefox)
I.e., Containers do NOT protect against some lower-level privacy vulnerabilities like plugin enumeration or history-sniffing that are mitigated more by using entirely separate profiles.