Notes has been left behind:
1. Notes cannot contain anything except plaintext
2. In OWA 2013, notes doesn't even have an app and, instead, is only accessible via the "Notes" folder in Mail
3. In OWA 2013, notes doesn't even have its own unique interface and, instead, uses the Mail interface
4. Notes created on another devices and initially opened in Outlook are opened in an extremely crude, 135 x 66 window in the very upper left-hand corner of the screen which is easy to miss.