Dominic Cooper's performance is something of a mixed bag; literally! He plays both the main protagonist and antagonist, often at the same time, which doesn't help either of his performances in certain scenes. Often, it results in long soliloquys by one character (usually Uday) whilst the other version of him remains silent and stoic, leaving the acting slightly one sided. Although Uday-Cooper is arguably more impressive, in my opinion he seems over emphasised and at times unrealistic. Latif-Cooper is a lot more subtle and less talkative than his flamboyant counterpart, however, his expressions and on screen emotion conveys a lot more depth to his character, and thus Cooper is definitely more convincing when portraying Latif.
The cinematography is gorgeous, ranging from the beautiful, orange hue of the desert to the racy, white lights of the nightclub, to the plain, whitewashed walls of Latif's palace prison. The locations are believable and the extras and minor characters are very professional and appear as real as you could expect. Overall, the portrayal of Baghdad is one of the most realistic I've ever seen in a film, and you never feel like you are watching actors in a studio.
Unfortunately, this is where the realism of the film and the ability for the director to stay loyal to the true story ends. The main product of this toxicity to the morality of the plot, it has to be said, is Uday. He is the worst thing about this film, but at the same time he is also the best. You just have to love the sadistic pyscho stereotype, you simply can't help it even if you know it's wrong and the character in question is extremely distasteful. The film would be boring without Uday, yet with him it seems so more false. Like Hannibal Lector, The Joker and Iago, Uday Hussein is portrayed as an extremely unstable, Machiavellian villain, in a position of great power. He is shown to be living the dream of cars, women and money, and more sinisterly rape, torture and murder. The film depicts Uday as cocky, manipulative and surprisingly, a tad metrosexual. This last quality humanises the character despite all of his inhuman characteristics and also glorifies his actions in a way, which isn't really a good thing when you consider the real Uday Hussein and the crimes he committed (some of which were much worse than we see in the film); he shouldn't really be misconstrued in this way.
Another thing that detracts from the true story is the plot itself, and the events on screen greatly differ from what happens in real life. I won't spoil it for you, but I can't help but feel that these changes were added to make the film more interesting and therefore accessible to a more mainstream audience. However, one thing I liked about the plot was the abolition of the typically cheesy romance story, although at some points the film seemed like it was heading in that direction.
Despite a few things which I've mentioned, I found The Devil's Double intriguing and exhilarating and I would thoroughly recommend it to anyone who is a fan of the drama genre, has an interest in Iraqi history/culture or who would just like to see an interesting film. Not being a big box office hit, I doubt it will be in the cinema for much longer, so if you don't manage to see it on the big screen then buying or renting it on DVD or Blu-Ray would be a good choice for something to sink your teeth into on a lonely evening, after work.