Loved the demo, bought the early access as soon as it was available, and my partner and I have been playing it daily since.
On the first day, everything was perfectly fine for me, and for her, with a slightly older video card, she saw some stuttering but lowered her settings and it was quite playable.
After the hotfix, she found that while playing, over time, and usually within an hour, she got a slideshow so bad, it gave her a headache.
Myself, I was mostly fine but I would also see framerates drop off, and while mostly playable, during ship boarding, things got really bad.
Today, day three of playing, she can't even sail, where as she was able to do so the last two days and it was literally about 1-5 FPS, and lots of activation lag. Her GPU was at 100% and really being cooked.
My GPU is ALSO being cooked at 100%. No other game I play even comes close to using that much GPU, ever.
Something is seriously wrong. I hope it gets sorted out soon, because I love the game.