I'll be that guy. The writing was completely off for me, I don't know if it was the Chinese sensibilities that I was lacking, or something lost in translation, or what, but I couldn't understand the main characters at all. The multipage scientific exposition sections do not make this "hard scifi" (and they're whacky anyway). I never got the hype, and I never wanted to follow through with the other 2 books.
I don't think The Martian and Three-Body should be compared. I think it's fair to say that The Martian is more 'hard sci-fi' in that the story is more grounded in what we know to be true. Three-Body has to invent some ideas in order to finish it's story.
That said, I overall enjoyed Three Body more. Even if it did push me into an existential crisis of some sort.
It caught my eye that you said 'book' rather than 'books'. You might not be aware Three Body is part of a trilogy? If you've not read The Dark Forest and Death's End, you are in for a real treat.