I wasn't let down. Really liked that it culminated into a giant celebration of music. There were waaaay too many cheesy moments, and I still think that the whole "the dreams were sending a message from the beyond" was contrived as hell. Overall, clunky, true, but brutally honest with its love affair with music. And with a solid roster of characters, this manga still comes out triumphant.
I'm just glad the anime didn't get this far. It would've been unbearable to hear a subpar singer get complemented on an international level.