I guess it should be clarified more. I have been using Orion for more then a year. Bugs are a general problem with the browser even the Beta version, and RC versions often get released with problems that forces me to use Beta.
So i think RC should more be seen as a preview of what to come, with or without bugs.
That said this isn't a bug, but a new feature, that for me personally is the desired behaviour.
So i guess the discussion that should be had here if it should be on by default