No doubt, this mangaka can not only draw superb, but narrate a well-pace story as well. It was like watching an anime (exactly the same as Death Note). The background and the facial and body expressions of the character are detailed. Besides, I always wanted to know more about the life of a mangaka, who are artist that suffer a lot too. At least, from what I read from the side-notes in any manga.
The only thing I am not fan is how the girls/women are portrayed, here as well as in Gantz. Not only how they are drawn (too doll-pretty) but like they are not really relevant to the story. But that is just my personal thought.
And it is impossible not to compare Mashiro with L, they look the same. Mashiro is L but with Sebastian Michaelis' hairstyle :D