Maybe it does hurt AMD a lot. I'm not having any issue though. Ultra everything as per the Recommended settings when I launched the game.
I have everything on ultra, with god rays on ultra, draw distances on max. It runs between 40-60 fps but can be bogged down to 20-30 when looking in specific direction (lots of npc's?). I noticed that the GPU load goes down and one CPU core runs at 80% load when the fps are lower.
After playing for a while I think that graphics are not the worst part of this game - voice acting is. Voice acting, lip syncing and all animations (anyone saw a jump animation?!). It is just terrible.