I just got done with this game this afternoon... I have mixed impressions. I'm not sure it is worth 40 just because I don't see myself playing it again. It was very creepy at first, but you kind of get use to it by Episode 4. The story isn't bad, a bit convoluted, but it will keep you going for the first few chapters just to see what's next.
I guess the end game was just a let down overall. Not going to ruin it for anyone, but I wanted more variety and challenge in the end, and a different resolution for the core game.
If you got the money, I guess go for it, but games with no online component almost always have huge price drops within a year, so if you have a backlog, I'd wait. You're probably better off waiting for the DLC to come anyway.