Ok, so the ending is "bad" in the sense that it will make you cry. I watched the last episode with tears in my eyes the whole time ... and then watched it again. Will probably watch it again tomorrow.
The main actors are amazing, no childish behavior as you often see in BL but real characters with real emotions. It just clicks on so many levels that I don't understand why people don't like the ending. Ok, so I guess it is not like in the books, but man ... Wayne Song knows how to portrait first love and the way he shows sadness ... it breaks my heart. Ok, I give in, need to rewatch it again now.