Listen, Cloverfield came out when the "found footage" style was extremely popular and prevalent. I don't doubt the decision to tell that particular story in that particular way. And in Cloverfield's case, it was pretty well done. I will say this, though: I think the style is, on the whole, very weak. It gets tired fast. I have yet to see a found-footage film in which these thoughts don't occur to me: "Why are they still filming? Why do they have a camera still?"
Films will find flimsy ways to justify it, sure. The main character wants to "document" this, so everyone knows what's happened. Look, I'm just saying I'd abandon a camera the very first second a monster started destroying my city. I'm trying to survive, not make a documentary.
The fact that 10 Cloverfield Lane doesn't lean on this gimmick really bodes well for its success. It gives the film room to be more artful, more careful with its shots. I felt more immersed in the world of the bunker, oddly enough.
