Well let's look at it like this.
As everyone has said Rage is the main reason why I pick SS over EM. Rage has the longer effect than build up. In a PvE purpose, perma-knockdown is much better than stunning. I can care less for PvP. SS and Stone can chain knockdown bosses which is a life saver. Also as probably previous stated, SS gets KO blow at lvl 8. That's 10 levels of early boss owning.
I think, NOT counting rage, Stone out performs SS. I may not be right, but I think it does. Stone powers are a true SMASH set. The screen shakes, the sound effects, and the fact that you completly knockdown mobs is a given. Pick up Air Superioty as a filler attack and you will be much safer than EM since EM stuns still allow mobs to run around dazed.
We all know EM has the best single target damage powers but come on, be original and not boring with the pom poms.
P.S. Does anyone else think that Fire isn't really a SMASH set? I mean come on it's lethal/fire damage heh. Every other brute set has some SMASH ing in it.