Session manager is the main one that's missing for me. Nothing else can reliably selectively restore a session with full history and unloaded tabs on startup after a crash for me.
Likewise, I will not go further with firefox until there is a working session manager. The one supposed alternative that is compatible has poor reviews and appears unreliable.
I might add that I was a nightly user for over 30 prior versions.
Interesting. I've never had an issue with the built-in session restore functionality. I'm not dismissing you, but asking what issues you've had with it (so that I can watch out for them.)
I might add that I was a nightly user for over 30 prior versions.