That's not it. Unity let you find at you typed to get to menu options. So you did not have to care whether the item you wanted was under File, Edit, or whatever, you could just start typing "preferences" and it would let you find it and go to it with the keyboard.
That is the single feature I miss the most about Unity. Gnome's prodigal attitude to screen real estate is annoying (though the Ubuntu version is somewhat better), but being able to search menus makes a real usability difference. I miss it every time I use InkScape or QGIS or similar programs with five layers of voluminous menus...
That went away with global menu, I'm afraid. In vanilla gnome every app handles it own menu however it likes, so this kind of integration is not possible.
For all its flaws, Unity really tried to offer an unified desktop experience.
That was pretty good, actually.