It's ok, but don't spend to much on it. Despite it's title, the movie revolves more around a sect worshipping demons instead of the demons themselves. They have very little screen-time, and are kept a bit in the shades. The storyline is decent, but don't expect much gore and killings.
It's more thriller than horror, and has to much drama and plain old 'running in streets chased by something vague'.
It has some impressive scenes and surprises, it remains a pretty ok movie to see on a lame sunday.