I just finished up Bioshock 2 and I really feel that the story redeemed itself in some ways. Immediately after the battle with the two ************, it became interesting all of a sudden. For the record, I saved all the little sisters and got the good ending. I hate to nitpick, but there was little to no emotion in that ending. When I saved all the little sisters in Bioshock 1, the ending was very emotional. I have to hope we see Bioshock 3, and I'm hoping that Tenenbaum plays a much larger role in the 3rd one. I felt she was a bit overused in Bioshock 1, and underused in the sequel.
As I said, I won't offer up a review, but I will recommend another trip to Rapture in any form. The sequel wasn't quite as awe inspiring and ground breaking as the first game, but it's a great game on it's own nonetheless.