The Perfect Sleep, while not a brilliant film does represent the ever-shrinking genre of watchable neo-noir. While it's certainly flawed, it lacks much of the intentional overly complex that robs many similar movies of their enjoyability (why watch a movie that's needlessly hard to follow?). Then again, it's not exactly a movie you can switch your brain off for.
Normally someone would put some sort of plot synopsis here, but if you've ever seen any type of noir film you know such an endeavor is pointless. They're usually a bit hard to follow and that can be part of their intrigue. Most noir-ish films rely heavily on the dialog (usually in ways that most people would never use in regular conversation), characters of moral ambiguity, and comparably lavish sets. The Perfect Sleep is no different, with the possible exception of most action sequences involving martial arts. Not sure I'd seen that before.
All in all the film comes out looking a lot like a seriously less flashy and more intelligent version of Sin City or The Spirit (the latter being complete garbage). That's actually a big plus for me as a fan of (some) noir films. While I enjoyed Sin City I always felt like it was just trying to do too much visually that took away from an arguably cool story, so that actually works well for me. Aside from the somewhat vague plot I'd say this would be at least enjoyable for fans of the genre. You don't see too many of these films these days and you see ever fewer done well.