More than the characters, this is the city of Camorr who is the real hero of the book. The descriptions are original, teeming and the city feels alive through the pages. Scott Lynch tells a setting so as much a story. We like it or not, I find that the descriptions are sufficiently integrated into the story alive and not to become heavy.
Locke Lamora and his companions are extremely selfish and greedy heroes. All have a lot of personality, but may seem unsympathetic because of their dark soul, especially in the first half of the novel.
That's warnings, if the above elements do not repel you, I recommend this novel, it is very rich, and engaging if you adhere to a minimum the mood Renaissance Venice.