I found the graphical representation of the revision history, with colors for net-add edits and a diff color for net-substract edits helpful.
I think it would be very useful to have a scale shown on the w:ordinate axis (Cartesian ordinate), in order to have rough order of magnitude of the ''size'' of the edit being reflected in the bar graph. Was it 10 chars? 100? 1000? 5000+? etc.