Looking Forward To It Batman: Arkham City - Harley Quinn's Revenge PC

Well, I've heard that this DLC isn't all that, but I want to find out for myself and I've got $10 to waste. Unfortunately, the already-convoluted purchase process - in which I bought it on Steam, but apparently must redeem my code in Games for Windows Live? - has failed me, because my code doesn't work.

Not off to a great start here, guys.