My first time through this house was one that I won't forget. I was in the front of my group, with a huge gap in front of me through the whole house. I don't scare easy, but I got at least 10 or 11 GOOD scares. At one point in a hallway I got a scare from my left, then a scare from my right, then (not sure if it was one of the previous two actors again, it caught me that off guard) a THIRD scare as one of them jumped directly in front of me as their face lit up bright from their e-prompt. A triple scare. I'm pretty good at seeing booholes coming up before I get scares (unfortunately), but in Dead End, some of the actors are placed very well and you'll never see them before it's too late.
Not to mention, this house is extremely detailed, but gets dark in the right places. I thought the use of the tunnel was pretty clever, although the effect isn't as impressive if you don't walk into the hallway with the right timing.
My second run through wasn't nearly as good as the first, but I still got more scares than I would on an average run through a house.
I think it's very subjective to say this is the "scariest house ever at HHN", but I think it is definitely close.