I personally really like the way Ubuntu menu appears when you hover over the title bar and how it disappears when you leave. The KDE 5.9 button on the title bar is kind of the same thing BUT you need to click on the button the see the menu titles, which become an additional step each time. I don't use the 'control button' in Dolphin and rather use the menubar which feels to me more natural. I would be a great addition to the KDE desktop to have a title bar like Ubuntu. What do you think ? Keep doing your awesome work ! I Love the KDE desktop (look/feel/customizability) !
*** This bug has been marked as a duplicate of bug 375951 ***