Since a few days after the game launched, once it actually got working, I managed a really solid 1080/60 on my ancient hardware, some areas even in the 80's, with the game looking fantastic with a mix of medium/high settings and couple at ultra.
Then after one of the patches I just can't seem to get the game looking as good anymore, blocky shadows in particular. Even with everything on medium and the demanding settings on low, I'm still dropping into the 45-50fps area quite often where I wasn't before.