It was very good but it was too bloated and the ending didn't work for me.
I think it could have been a 5 out of 5 or a nine out of ten if twenty minutes were cut from the movie and the ending was more conclusive.
Overdoing the twists and plot turns seems to be a recurring theme in Fincher movies. He also did it in The Game.
He really should listen to the maxim "less is more" sometimes.