Pretty nice. I only had a little over an hour to play with it tonight, my settings are all at high with a few set higher, Like I knew I could go ultra on textures and I switched to hbao+. I am using the AA and motion blur but I am keeping blur and sharpen off, imo they just do nothing but hide the original image information. My frame rates have been really high for all scenes except the ship and the portal which looks like it was just a badly optimized scene.
So far the AA and shadows are nice, although I am hoping something can be done to get some shadows on all grass, and not just bushes and up (flashbacks from oblivion days). IMO the most impressive thing I have seen so far is the sun crawl. The game has long days which I love because it means I can spend my time doing what I want without worrying about NPCs disappearing suddenly because 15 minutes passed and its night time (I'm looking at you, skyrim!). Previous games have either updated the light direction and shadows at either a much slower rate then the framerate, or in games like GTA the game uses a heafty dose of low resolution shadows to keep the frame rates tolerable. Witcher 3 uses some pretty detailed shadow mask textures with an impressive smoothing filter and at the same time has no problem with a sun that updates at least 30 times a second.
One thing that is kind of a let down, the foliage animations do not create a convincing effect of wind, there is always that one wild bush and it seems like every plant has a mind of its own.