I saw it last week and right after watching it I wasn't to sure because the violence and gore had been so in your face, I felt I'd missed something.
If you want a gore fest, you should be quite happy, although after the hype I expected more. I mean it was scary but it was tension and plot that wound me up, not the nasty stuff.
I was also quite happy that there was a plot, I wont spoil it for others but they could have quite easily just spent an hour going over torture scenes and failed escapes.
BUT there is a deeper side to it. Consumerism. Did you think that there was a link between the brothel scenes and hostel scenes - the paying for flesh, long corridor shots, the hookers table of instruments compared to the torturer's table?
Also the way that American's cost more to kill, reversing the role of America as an economic superpower and making them a product.
I know this might seem over the top, but its not uncommen for movies like this to also include a subtext. It doesn't matter if you want to see the subtext as you can take from it what you want.