The "context bar" seems like a huge win for people who look at the keyboard (who do comprise a huge fraction of the market), and a huge loss for touch-typists.
That said, I also don't use that many function keys, and I've slowly started remapping the keys I care about to other key combinations. In practice, I care about a few sets of function keys, most notably F11/F12 (commonly used for fullscreen, which I've now remapped to Super-F), and F4 (Alt-F4 to close applications, for which I've now trained my fingers to use Ctrl-W or Ctrl-Q and report bugs on the occasional application that doesn't accept those).