The side bar icons option is making the new bar much more useful. I got my real estate back for my monitor. Got dual page with near full page showing and the only gripe i have is the open pages at the bottom of the bar. it lets me show only 2 open files when i have 5 open.. it does not resize beyond that. With no way , i have found, to expand it even if there is room and there is..
The Document Bar can be resized if you right-click the toolbars and click “Customize Toolbars…” You can then use the down arrow at the bottom of the toolbar area to scroll the toolbars. The Document Bar will unhide, and you can resize it. Use the down arrow repeatedly if necessary.