Cast a charisma buff, or use a charisma item. That causes a big spike locally.
Attack with haste, you will see your weapons delayed on their animation versus your characters limbs.
Be tactically active in spell combat; see all sorts of rubberbanding.
I think there is a hit detection issue going on that has been around since they took Mabar down the first time (before Thanksgiving), or even longer. This I think is what is also causing players and enemies to rubberband outside of the environment.