The only time i get true framerate screwups are doing S-rank hunts, if i forget to turn off outsider VFX, in which case my PS4 hits worse-than-ps3 level GPU struggle.

I personally noticed slowdown in the coearthas area, in the spot where the entrance to snowcloak is. There is nothing in the area that could ever cause the PS4 version to dip, but it gets noticeably low over there.