Theoretically Arms, but you have to be in a group that positions well and need some luck on your side to really see the benefit (meaning you need them down together during Execute phase, and be able to keep up with the movement to cleave them).
Fury on the other hand is much easier to play and should always do well, but doesn't have the same potential Arms has.
Short version: Arms can either do very well or very poor, Fury is an easy middle ground.