A very old plugin that "smoothed" out movements was one that adjusted the "Path Precision" part of honorbuddy depending on your current speed in-game.
That has since been integrated into the Honorbuddy core so if it is still moving to a point, stopping, then moving to the next while using GB2 it's probably just your WoW client loading all of the objects around it too slowly. Try turning down your settings and shrinking the wow window to lessen the load coming from it. It may also have to do with your network connection loading slowly.