It was a good option to add a hide menubar option, but it wasn't intuitive if the only way to enable it again is the Ctrl+M shortcut. There should be another method of showing it again or replacing it altogether through more intuitive ways. Adding a right click option to the toolbar/locationbar would be odd since the only menu to show would be "Enable menubar". A replacement button to toggle menubar's visibility will however be more odd. Another issue would be the need to show again the menubar whenever the user need some functions only accessible to the menubar (of course, should not require the user to memorize keyboard shortcuts as not everybody is accustomed to it). There are users who prefer not to see the menubar at all but there will be times that they will be needing it. It would be nice to add an extra gear button when the menubar is hidden, replacing the menubar's function altogether and adding an intuitive method to make the menubar visible again without the need to use a keyboard shortcut (the sole method of showing it again). This button will be hidden again once the menubar has been made visible again.
Its an option to un-clutter the interface, not for the sake of adding another button.
Just had inspiration from Firefox 4's UI change so I made this issue. If the menubar is hidden, there should be a way for users to access these features via mouse (or at least a way for them to restore it intuitively) I don't have that much idea about your design principles, but some users might get stuck if they don't know that the 'only' way to restore the menu bar is via a keyboard shortcut (Ctrl+M). If adding a button is not an option, it would be nice if: 1. We add the whole menubar functionalities via context menu on the toolbar (GIMP style) 2. Or we simply create context menus for showing or hiding the menu bar (context menu on toolbar) along with other display options like sidebar visibility and location selector styles. Personally, I don't have real problems with it but users who really depend on their mouse and clicked on the sinister hide menu bar item might never find a way to bring back our old trusty menu bar.
*** This bug has been marked as a duplicate of bug 13868 ***