I played this demo at CES and the animations and fighting looks gorgeous and smooth. There are no framerate issues and you will never miss those extra p's.
The only thing that surprised me graphically is that the backgrounds still are a little wallpaper-y. Kratos and enemies still skate a little on top of the ground/backgrounds. But the fighting is very smooth - much more so than DMC4 or especially Bayonetta on PS3. No signs of any slowdown, even with several enemies at once and lots of effects from attacks and the like.
A very pretty game in motion. Graphics lovers will not be disappointed.