Installed it and for some reason images in Twitter don't show. Disable and refresh and they show again. Must be affecting it somehow.

yep, same as a few people, i can't log into facebook any more. not seen any support available for this issue either.

It certainly did a good job of containing facebook - It logged me out and then prevented me from signing back in again. Even after disabling the add-on.
So I guess it depends how much you like facebook. Or if you want more free time and an enforced social media detox...