I've just read Monogatari series and one of the things that I noticed was that it's very dialogue heavy. While this is supposed to be dull in theory, I found myself finishing the book and wondering where the last hour had gone. For some reason, it's very hypnotic.
He also wrote a spin-off novel of Death Note, called "Another Note". It has more dialogue than average novels, but it makes sense there, since most of the story is conveyed through the protagonists talking.
http://ka10.de/b/files/LABB.pdf (reading it won't make much sense if you never read or saw Death Note)
I cannot judge his writing from a single book, but what I like is that he created a story out of two characters, one of which appears in only one episode (Naomi), and the other one (B) being mentioned only in a single sentence in the mangas.
His Zaregoto series is one of my favorite series' of all time. The characters and themes are al great in his books, I absolutely love him and his creations.
