General UI, toolbars and menus
Glade's new UI has merged menus and options into a headerbar. This follows the new trend in UI design, first started with devices with small screens (to save space), which does not necessarily accommodate the needs of people who use, or want to use, glade for serious development. We are paying less than 120 USDs for 24-inch screens. We can spare a 24 pixel row for a menu that gives quick access to options in a logically organized manner.
Part of the goal and benefit of a UI is to make options easily discoverable. Menus and toolbars, while old, are perfect for this purpose. The current design, which hides options away, is less organized, harder to discover, and less uniform across applications.
I haven't found any option to re-enable the menu-based interface. Please, consider bringing it back. It'll make glade easier to use.