The PA movies, which I liked even less than
Chronicle or
Cloverfield, were different because they were trying to use the same filming style to touch on a slightly different nerve - that being the scare impulse.
I just thought
Cloverfield and
Chronicle were basically trying to stimulate the exact same nerve endings in my brain, only
Chronicle did so via a superhero vehicle instead of a giant alien. Just to be clear here, I liked
Cloverfield and
Chronicle to a very limited degree, but neither of them were worthy of the immense praise that I've seen some people (mainly teenage fanboys) lavish on them, and if you want my opinion, I think
Chronicle was more or less a "me too" re-telling of the
Cloverfield story, but through a slightly different lens.
Also for the record, I did enjoy how they treated the superhero thing in
Chronicle differently from many other superhero movies, but c'mon - it's not like it was unique. Ever seen "Unbreakable"? Ever watched "Heroes"?
Plus, the so-called "tonal shift" in the movie was, to me, little more than an attempt at finishing strong with the teenage crowd through some good old-fashioned action to make up for the fact that they dropped the ball on character development. I was interested in the characters for a while, but when it became an all-out slugfest at the end I was somewhat disappointed. The filmmakers could have done better than that, which to me comes off as being a bit lazy.
But, glad you liked it. To each his own.