anchor point and handle display - no visible difference on screen
With CC 2018 update there is NO visible difference with ANY of the 3 options of the ANCHOR POINT AND HANDLE DISPLAY dialog in preferences.
THEY ALL LOOK EXACTLY THE SAME ON THE SCREEN!!!!!
Ashutosh Gupta (Illustrator Team) commented
With version 22.1, there is feature preference added for anchor point and handle size under "Anchor Points, Handle, and Bounding Box display".
You can update to latest version of Illustrator to use the feature