Koi Kaze was a pretty good adaptation, but the ending was a bit darker in it's implications.
Overall, it might not be the BEST VN adaptation, but YnS is still my number 1 favorite anime.>Incest>Cute girls>Sister wins>Pretty good animation, with CGI that you can safely ignore>A fucking AMAZING soundtrack
Hell, all of the incest series and VN's have great soundtracks.
By the way, there are the character songs for the sequel, i'm uploading them to dropbox now. Sora's is the best, FYI. And that's not even favoritism speaking, it's just fact