User blog comment:JmLyan/Sairei, the Dimensional Mistress/@comment-5493192-20140424173717/@comment-7481207-20140425082732

The answer to both of those questions is yes. Its major use is as a "safety net". If something goes really bad, you can attempt to avoid that or try a new tactic, or perhaps even avoid the team fight altogether since you know you can't win it. That said, the enemy team also knows the outcome of those 5 seconds which means they can adapt as well, making the only real advantage that you get to decide if the 5 seconds will happen or not.