We are heavy users of notes on many of our entities.
After upgrading from 2011 to 2013 adding notes are a disaster.

If I hit Enter it saves the note. OK, let's try shift+Enter for a new line. No, still just saving the note.

It is difficult to write good notes with no line break. Rich text editing and a either a save button or enter for save and shift+enter for line break would have been nice as there is pretty difficult to read a long notes without line breaks. The CRM is our working tool, not Twitter.