With no way to revert to the prior version of the game I have to assume that my memory is correct and that the framerate around Old gullet sinkhole didn't tank prior to the current patch. Because of the quest that requires you to be near the location I think I would have noticed the problem the last time I went in to unlock the chained door on the rim (and kill the deathclaw down below). I am not running the most powerful of computers (AMD FX6100 black, 8GB ram, Radion R9 270X 4GB) and can maintain 30-60+fps for the most part. But until this update I never fell so far below playable that mu companion was able to get full lines of dialogue out without a frame change, and yes I am including the abysmal frame rates that are associated with the mandatory vertibird flights (I usually have been dropping to about 10 or so fps on them).