I thought it worked well as a "disturbing" film, and is well directed with suspense and some satisfying scenes of revenge. It would've worked better though if we actually cared about the characters because they are just a bunch of American jerks. :p
Hostel is a very nice film. And the most disturbing about it is that what you see in there, happens acctualy in the real world. The revenge scenes are excellent and very satisfying. Highly recomended!