LOL, I never expected to hear death metalish growls in an anime opening song.
As for the episode - not good. These Yotsuba dudes are simply worthless adversaries for the main characters, leading to large levels of boredom. And them agreeing to postpone the murders seemed like a copout to me, forcing L and the rest to choose between allowing the murders to happen and making his move too soon would have been much more suspensful and would have allowed for more character development, IMO.
And I am convinced that Misa is practically braindead but even for her accepting such a suicidal mission was almost too dumb. But she is in the new opening so we know she won't die soon which is too bad.