It's Nolan's weakest but it's still a very good film, I'd still give it a 7.5/10. I think with the Following,it's his least interesting work for me. You can tell this was made to show the studios he can work with a big name cast and work under a studio, it was probably a audition for the Batman reboot. Plus I prefer Stellan Skarsgard's 1997 film just cause it's a lot darker and downbeat.
The good things about it , Robin Williams is a very good sleazy villain, Nolan does a great job at keeping OTT Al Pacino under wraps and gives one of his better later years performance. Great to see the hugely underrated Martin Donovan, Nicky katt and Maura Tierney give good performances in small roles. I still think Hilary Swank isn't great in it, I think Nolan should have cast someone younger then Pacino maybe a Guy Pearce or Russell Crowe and played the role more like Skarsgard's Cop, a corrupt Cop who doesn't remorse killing his partner, who sexual abuses the flirty young teen girl, Sleeps with the Hotel woman (played by Maura Tierney in Nolan's Film), who teams up with the killer only to turn on him in the end and doesn't learn anything at the end of the film and goes on his merry way. Maybe it would have been to dark and downbeat not to have a flawed but heroic cop instead of a lowlife cop.
It's still a entertaining film and worth a watch but it be certainly down the bottom of many peoples list concerning Nolan's films.