I found this to be a step down from Insidious. It's so similar that I felt a serious sense of deja vu--and not in a good way.
Both films really fall off the cliff in the third act. Wan just doesn't know when to stop. I thought Insidious got off to a great start before it went off the rails with the goofy tonal shift. But I found the last third of The Conjuring even less appealing. It completely disintegrates into noisy special effects overdrive. The best ghost stories don't over-do it. The end of The Conjuring is like a WWF version of The Legend of Hell House or The Changeling. It was way too manic and overwrought for my liking.
In the end I don't think either film is very good. But Insidious has the better boo scares--which seem to be Wan's specialty. Nothing in The Conjuring is as effective as that face in the window. And Insidious seems to unfold a little more naturally. The Conjuring ultimately tries a little too hard for my liking. There's no doubt that it's a more tonally consistent work than Insidious. But it seems like an extension of the same material, themes, and techniques. I found them all less effective the 2nd time around. And although I didn't think it was possible The Conjuring offers up an ending that's even more hokey and unsatisfying.
Maybe Ti West can teach this guy some restraint.