One of the major problems with `The Double' is the trailer advertising it. If you've seen it, it tells you most of the story (and one of the twists). However, I only found that out by reading the internet forums about this movie. I suppose I fortunate enough not to see the trailer, hence I quite enjoyed finding out what was happening as it went along.
It's nothing too revolutionary - old dog spy (Gere) paired with up and coming spy (Grace) - it's effectively a mismatch/buddy-cop film but with spies. It flits between action and talking, with a few surprises thrown into the mix. Plus it isn't too long, so it fits everything in and quite nicely.
But, although it's a decent watch, it probably could have been better. It gives away one of the surprises too early, which may lead some to lose interest. However, at least there are a few more twists to come which I'm guessing the writer hoped would make up for it.
In short, it's not bad, but not a classic. Plus, avoid watching its trailer at all costs. Long gone are the days when a trailer is made to tease and draw you to a movie without revealing anything. I decided to watch the trailer AFTER I'd seen the film and I can see what people meant about it. I really don't know what the film-makers were doing with the trailer - it's effectively a ninety minute film condensed into a couple of minutes.
Overall this is a decent and entertaining production for which you have to keep expectations low on all levels in order to enjoy it.