Rated 5 out of 5 stars
Very nice. I too am annoyed when I (re)start Fx with a whole bunch of tabs, as it takes forever to finish loading them. Now I can start up Fx quickly and only load the tabs when I want to see them.
The auto-unloading feature (unload an inactive tab after a certain amount of time) also seems like a nice idea. I haven't observed it in action yet, but I have enabled it and believe it will be useful.