It's typical Zola. The first half of the book is stronger than the second, which is unusual for Zola, because his works tend to get better as they go along. The character of Renee is well done, and the fact that her tragedy ends up being a farce is clever. The description of wild speculation in Paris is good, but I suspect that while I greatly enjoyed the novel it will not live in my imagination as some of the other works that I have read by Zola will. Probably only for the die hard Zola fan, which I am, so I am still going to rate it quite highly.
Still, I think that Zola is a greatly under appreciated writer despite his numerous flaws.