After 15+ hours with Fallout 4's latest expansion, Far Harbor, we've got a fairly good impression of it. The story is mysterious and intriguing, the new monsters are mostly terrifying (in a good way), and Far Harbor is fun to explore, at least in terms of the environment. Unfortunately the same can't be said for the frame rate.
Yes, we all suffer at least a few slowdowns once in a while in the base game, but this time it's horrible. We were fairly fortunate in the base game, and barely noticed it, but it seems like karma decided to even things out this time. Our PlayStation 4 edition often drops down to 10-15 fps for minutes, even while just walking around, before giving us a short break with "smooth" 30.
We've contacted Bethesda, and they're aware of the problem. They are apparently working on a fix as we speak, so hopefully we'll get a helpful patch very soon. Till then we advise PlayStation 4 owners to be wary of spending their money on Far Harbor. PC and Xbox One owners on the other hand should really consider purchasing it. The expansion brings more of what we love in the base game, with a few extra goodies.