Likewise with the PS3 version. The framerate has its dips, but it's generally hardly even noticeable. It's only when there are a lot of enemies on screen, and spell effects going on. In Gran Soren there are dips for no apparent reason, though.
I have to say, the game runs way better than I expected it to. The demo definitely ran at a lower framerate than the actual game does. Never once has the framerate affected the gameplay, it's only occasionally ugly looking.