Well, I just finished this VN. I have very conflicting feelings about it mostly because of a few issues in the story I did not agree with.
While I did enjoy the past story and the new characters that story line introduced, I did not like how Ayako was handled in the present story line. Yes, I know she had her personality changed and decided to live as Fuyumi, however, she seems a bit selfish now and only cares about her own happiness. Maybe I'm mostly upset because I wanted her and Ayato to somehow become a couple again and am a bit bitter about it.
I also didn't like Yukiko anywhere as much as Toko, and am very upset with the true Toko end, even though it was obvious she wouldn't be found alive.
Overall though it was a very good VN, excellent writing and characters. A few issues hold it back imo, which make it not as good as KnS 1