The UI redesign, while generally nice, brought up one serious usability regression: While the menus are displayed right-to-left, the navigation and zoom boxes are still left-to-right.  This leads to excessive mouse-pointer-travel times.  E.g., I am switching from dual/fit page mode (which I have as my default), which allows to quickly navigate to the page you need when browsing long documents, to single/fit width mode, which is sometimes required to do careful reading of intricate documents.  

Now the fit width/fit page button sits on the left side of the screen, while the dual/single sits on the right side of the screen, almost maximally separated from each other when using a maximized window on a wide screen.  

I can see several ways to change/alleviate this problem:

- Move all controls left-to-right or right-to-left (it escapes me why right-to-left is now the new fad du jour, but that's probably a GNOME thing.  Not that I really care, but such a decision should be applied consistently).

- Bring back the user configurable task-bar buttons.  (They always looked hackish to me, so I am not complaining that they are gone, but at least they allowed me to set up a pretty efficient work flow and one should seriously look at how a consistent user interface can be efficient in the same way.)

- Set up keyboard shortcuts for fit width/fit page and for dual/single.  (Maybe they already exist, if so, make them discoverable.)

- More ambitious, would be my favorite: create a scale of logical zoom options (which must be dynamic as they have to depend on the aspect ratio of the window) where the physical magnification changes monotonically as the user flips through the scale, with dual/fit page at the bottom and single/400% at the top.  Dual/single mode would be switched on and off as part of the zoom scale; the n% options would only appear explicitly once they get to a larger physical magnification than fit width/single.