So REC was really something special, but it was a collaboration between two directors. And I do have mad respect for the other one who had "Nameless" and "Darkness" already under his belt. So Paco here goes full horror with this and the end result is quite decent. It's not really anything new you get or that interesting (possession, demons and so forth).
But it does work overall. So while it may not change your world view or shake your film world, it is something to watch, if you are into horror movies. There are quite some neat jump scares and the story has the right mood overall. The acting is also decent enough, it builds as expected and there is nothing much that is wrong with it. Except for its predictability I guess. So by the numbers, but better than off the rails