I know I was harsh on Countdown when it first started, what with Superman telling Jimmy the secret identities of Batman's first sidekicks and the general bleh I feel towards most of the story(ies?). Now, though, I feel as though I have read enough of it to truly say it's just not that good.
When other books have "A Countdown Tie-in" slapped over their titles, you expect Countdown to give you the main story that the book is tying into. The thing is, when you read Countdown, it seems as though the book is a tie-in to other things, leaving you looking around for the whole story.
I think having a book dedicated to "linking" the DCU is a ingenious idea, but it's being done poorly. The central story is broken up into so many side pieces that are known to not be resolved in the series or until the very end that most people will probably wait until that mini-series comes out to read the story. It makes reading Countdown weekly seem like treading water. As it stands, Countdown could have been a series of back-up stories or inserts and would probably have been better received.
Just my opinion.