1. I do not quite like the fast phase nature of the flow of the story, that is complexity is introduced too much in CG even in the early episodes and I somehow miss any emotions from that anime from the beginning. Although I know CG is a great complex anime, but my preference is more like a Shinsekai Yori, or even Death note: Where the story builds up from simple premise or idea to a more complex one.
2. Character Design: I don't quite like how the characters are skinny and not quite proportional in CG. I prefer more like typical shonen design such as Naruto etc.
3. Music: Judging from early episodes, the music does not suit my taste. I prefer music such Shinsekai, tokyo magnitude and Bokurano, which is more into classical, melodic, warm etc.
In essence, I like dark, warm, empty, hollow feelings in anime with such simple-complex flow storyline. Music and character design also plays pivotal role for me.
These are all IMHO though.
I may be wrong and should give it more tries :)
Im hearing a lot of positive reviews about this anime and I have seen in this in favourites list of my friends so I am going to give this series a try!
EDIT: Look even @phil mentioned it in his earlier comment. Just noticed it now^^
To the admin there, sorry to make this as if like private game, I just cannot wait to response to Cool_Dude to strongly suggest him Watch Shinsekai Yuri as soon as possible!!! SSY is my ONLY MASTERPIECE in anime for me, my most favorite anime. Im SSY number one fan.. So yeah, please do watch it ^_^
PS: Cool_Dude, Look at my profile to see my expression for SSY, and don't response to this reply.