Also you'd get a free spot check or listen check if something in the room changed. Suppose an invisible rogue came in the room while you are all fighting some monster. Since everyone else is fighting, and not declaring "I spend my move action to listen to see if I hear invisible rogues" they have 0% chance of noticing. You, however DO have a chance to notice it (however small).
Also, don't forget the +2 Init bonus. IMO, this feat is WAY better than improved init for what it does (keeps you from being surprised in combat, AND gives you better init.)