First of all, this film is good, but, for me, it isn't as scary as The Conjuring. The reason for this, has to do with the idea of isolation. In the original movie, the house was large & isolated. Fear & isolation are a potent mix. Plus, the demon jumping off the wardrobe, was a real heart stopper of a scene.
Somehow, the fact that the house in The Conjuring 2, is in a built up area, and that the family have an extensive support network, reduces the fear factor.
I also found that the UK drama series called the Enfield Haunting [2015] was a better crafted account of this event.
Having said this, the Nun in The Conjuring 2 is just about the creepiest character, I have seen in a horror movie for sometime.
Especially, the scene, where she is at the end of the corridor with the flowery wall paper. I genuinely had a feeling of dread, whenever she appeared in a scene. In fact, it is almost worth watching the film, for this character alone.
I also felt that the character development in this film was really strong. I had a deep emotional attachment to many of the characters, including the Warrens and all the members of the Hodgson family.
So, overall, this is good film, with some scary moments.