Nice work. One nitpick is the "Saving..." text with the spinner is very distracting. My eyes shoot up and look at it every time. I have a personal feeling that displaying "Saving" text represents a lack of confidence that it will actually save. Since it's there my eyes go look every time to make sure it _has_ saved. If you feel it is important to display to your users their work has been saved.. show a subtle timestamp or something with the last save date, but remove the spinner.
