For me it works pretty well. You must disable permanent private browsing mode though, containers don't work in private browsing mode. Please be aware, that if used improperly, this poses a huge privacy/security risk, so only proceed if you know what you're doing. I personally use the temporary container extension to have something similar to private browsing mode, while still keeping the ability to use containers.

I'm using Multi-Account Containers and it works pretty well. (I simply installed it via the official Add-on page) You must disable permanent private browsing mode though, containers don't work in private browsing mode. 
Please be aware, that if used improperly, this poses a huge privacy/security risk, so only proceed if you know what you're doing. 
I personally use the temporary container extension to have something similar to private browsing mode, while still keeping the ability to use containers.
Also its worth mentioning that containers doesn't isolate everything 100%, things like HSTS Flags, OSCP Responses, HTTPS certificate overrides are still shared across all containers and except for the latter they probably won't be fixed in the foreseeable future, at least not upstream.
(I think the Tor Project has some patches for this stuff, but idk if they are/will be included in tor browser.)