Shinsekai Yori is probably the best example to hold up when warning someone off the "anime is a genre" trap. Because it should not be viewed by people who simply consider themselves fans of anime and manga. Not to say those common elements don't exist, but there is a far better, more descriptive way to explain it.
Shinsekai Yori is a masterpiece of science fiction.
That probably won't sit well with some people, but it's the truth. At best, you can just broadly say it is in (more socially acceptable term) speculative fiction, but Shinsekai Yori is the definition of what science fiction is: It uses fantastical elements to explore the human condition in spiritual, sociological, and political ways.
Once again let it be said, Shinsekai Yori is a quality show. But it cannot be recommended to -everyone- simply because it is a pretty anime. If you are not a fan of science fiction as a concept, Shinsekai Yori will probably not sit well with you. The most apparent problem with this is the beginning. It is slow in the terms of plot. That is because, again, like many science fiction novels, it chooses to focus first on universe building. This isn't any worse or better, it's just the stylistic choice of the novel, and the show sticks to the novel quite well.
Speaking of which, there are lots of elements that will feel like a book on screen, the least of which aren't several time skips that most television seeks to avoid.
Even among all these warnings: Science fiction fans who -want- something intellectually challenging may be put off by certain details. These are almost always cultural differences. Without spoiling, but as a general example, whenever the government or ruling body holds a policy that treats people as inferior, expendable, or second-class in some way, in anime it is typical that it slides by without much comment, merely being accepted as "for the common good" (this occurs a lot in Ghost in the Shell). Whereas in Western sci-fi, that is usually the sticking point for most plot twists and paradigm shifts. That is not to say there is not an opinion presented, but it is not -direct-, and that can infuriate some science fiction fans. So, advice towards them: Go in without expectations.
It is also science fiction in that the plot is the primary device, not the characters, though they are well developed enough to sympathize with their plight and even pick favorites.
There is indeed homosexuality presented. But again it is mostly in a sense of showing how different this society is. On top of that it is not fan-servicey in the least. In fact, though I am a considerable distance from a yaoi girl, even the boy-on-boy was endearing and tastefully handled, in my estimation. It would do the entire industry some good if more television handled it this way.
One thing that I can't praise the show on much is the animation. Though I only jumped in around episode 17, I marathoned the entire series in a night. But nothing particularly jumps out at me as a "moment of badass" for the series. Other than the flashbacks during the "introductory" phase of the show, which were quite effective and chilling in an Akira tone.
I will again say: if you are on the fence about this show, it comes highly recommended. But if you are vehemently against any of these stylistic choices (the sci-fi nature, the novel-on-screen, the plot-as-driving-force) then it would be hard to blame you for not enjoying it, it simply is not for everyone. But neither is The Lord of the Rings, Citizen Kane, or Batman, but that doesn't make them bad.
