If you take the game for what it is, an "Interactive Movie", you will find this to be an awesome experience.
The experience is unprecedented because you have an overall plot and continuously paced story like a movie, but a more detailed plot coupled with the ability to influence events and endings. Allowing you to play increases tension and the overall mood and atmosphere.
The writing, characters, and the themes, etc. are all memorable. The lifelike facial expressions that was heavily advertised is a little overrated and doesn't really add to anything. However, this is definitely worth a try for PS3 owners. It definitely seems a love it or hate it type of game.
For the current cost of around $20, I'd definitely recommend a try. I'd try renting or borrowing it since it only takes a handful of hours to complete one go-through. It can easily be replayed again to get a different ending although once is enough.