I personally find the fullscreen feature to be beautiful in appearance but inconvenient otherwise because I have no fast, elegant way to get to bookmarks. I could have the sidebar open, but I never use the sidebar, personally, so that means I'd have to switch it on and off regularly. I could keep alternating with F11 (but maybe I don't do that because I have a global macro in use on this key). Toolbar customization is no doubt in the works, but that's a long way off, so a very small bookmark button (preferably just for access to personal toolbar bookmarks--would be faster than having one more level to go through) probably wouldn't tick anyone off for being there and many would like it. Then fullscreen mode could actually be a feature that people found themselves not even switching away from most of the time, and thus it would be useful.
Please search for existing bugs before filing with the bugzilla helper. thanks. *** This bug has been marked as a duplicate of 132187 ***