I picked this up because I knew it tied into the Blackest Night storyline. I shouldn't have bothered.
This really a bunch of random stories, and the Blackest Night connection at the end is, by far, the weakest of the lot. Not that I was fond of the story that put Batman and Superman in a dream alternate world made up of not-entirely-clever amalgamations like Lex Joker (sigh) and Aquaborg (SIGH). Nor am I a fan of the nightmare storyline, though it's slightly better. The only good story in the collection is the Robin/Supergirl teamup. Otherwise, it's just not worth it.