I have had problems implementing FOSFacebookBundle, exactly with the connect option... which was not persisting the tokens in the users entity (FOSUserBundle) without extensive overriding of provider methods.
On the other hand HWIOAuthBundle worked like a charm, the downside of this one being that it needed a bit of work to make it look like FOSFacebook.
I even read a comment on a blog... or github bug report... can't remember exactly, where a FOS dev encouraged the use of HWI bundle because it's being maintained and developped in a better way then the FOS one. (found it. first comment on this post https://coderwall.com/p/qkdzca)
Way to setup HWIOAuthBundle that works: https://gist.github.com/danvbe/4476697