That doesn't solve the real estate problem - in fact it makes it worse in some apps. The top bar is still there after you do that. It just moves the menu items

That doesn't solve the real estate problem - in fact it makes it worse in some apps. The top bar is still there after you do that. It just moves the menu items back into the window. I don't really care where the menu items are. If the top bar would auto-hide, I'd be fine with it. I just don't want to give up the space. Apparently there's a modified Unity called "Unity Revamped" which adds autohide as an option to CCSM, but it's a slightly older version of Unity, and for whatever reason I can't downgrade to it.