On live I had a Grav/FF with Dimensional Shift, I used it for agro control when agro goes way out of control.
Scrapper gets bored, agros another group and people start dieing, pop it at the new group. They are out of the fight for a few minutes.
Only have one tank and he gets Alphaed, pop it. You get time to let the tank Rez and get back in the fight.
Only down side, if your team doesn't know to switch targets, they end up attacking an untouchable enemy.