Dude so like, I love the fact that the concept of two pilots is not only used to give us two characters to watch and interact with but it also allows the movie to flesh out the characters with actual scenes that detail their back story and explain their motivations. Instead of just boring exposition sequences.
Like, in most movies you would have a scene where Character 1 would reveal something from their past to Character 2 and would go on a long dramatic speech detailing something that happened to them or explaining their view on a matter. And you know what? That's fine for all intense and purposes but for a movie as visual as this, it slows the pace of the movie and just doesn't work. Or in another movie you would have a flash back showing something that happened to Character 1 while Character 1 narrates it to Character 2. There's nothing wrong that that either, and it likely would have worked in this movie but in Pacific Rim they managed to do just that. However they did something that both showed the flash back and it also tied into the in-movie fiction.
So you have Pilot 1 and Pilot 2 sharing memories and during one dramatic moment, we watch a memory of Pilot 2 and it's used to both flesh out her character, explain the motivations of her and another character, and also builds the relationship between the two pilots. ALL IN ONE SCENE! And best of all? It works within the context of the movie and doesnt feel jarring or out of place!