It requires many clicks to filter by context or project. There should be a shortcut in the action bar to filter by context or project.
I have some done some UI updates on my clone (brach ui-updates) one of them is that the filter actionbar is always open. This makes it a lot quicker to filter (no need for the Menu->Filter journey)
Happily the Filter button is now included in the Action Bar as of 57e30c6