An add-on that completely misses the point
Heavy Rain's main strength was the breadth of its story and the time that you spent getting to know the characters. This little bit of DLC has none of that, and is instead a 15 minute sequence featuring Madison's investigation of someone that she suspects of being the Origami Killer. She does this by entering his house and poking her nose where he would rather it wasn't. It manages to pull off a strong atmosphere of its own (a few disturbing and panic-inducing moments) but it feels like it is trying to cram them all in and get you back to the XMB as quickly as possible.
Gone is the complex pacing, gone are the drawn out consequences of your actions. This is nothing more than a single segment of the main game, and I mean that literaly. This was featured prominently in an early trailer of the game.
The add-on has seven different endings and encourages you to get them all (no trophy for this by the way, not that it's important). but that wasn't really the point of Heavy Rain. There is only one ethical choice to make, and that is whether to actually enter the guys house at all. Therefore the decision is "do I bother to play the add-on or not?"
If you want to be put through various levels of panic for 15 minutes, this DLC will do that. If you want more Heavy Rain, go play Indigo Prophecy. It only costs a little bit more, and doesn't feel like a waste of time and hard drive space.