People are telling you to make your decision based on the demo and I don't think you should listen to them. Maybe play it to see if you like the feel for the gameplay and if you do even somewhat, you should get it. If you don't have lots of money wait for a price drop or rent it, but this game is really good so far.
The shooting feels better than most third person shooters in my opinion. The only issue is some of the movement and the controls, although the control issues might just be me because I've been playing Max Payne 3 so much. I haven't even gotten into the story much, but so far the voice acting is top notch and I'm very interested in seeing what happens next. Also hearing that the story is good from reviews and a friend of mine gives me high hopes.
The multiplayer is enjoyable, but I won't play it much. I have better multiplayer games. Can't wait for the free co-op DLC in August though. That's why I'm glad I didn't just rent it.
You should definitely consider picking this up when you have some extra cash.