Saw this in IMAX, although I don't believe it's necessary for this film, but extra crisp picture and sound made it more tense and some unexpected loud sound makes you jump out of the seat.
It is an intense drama/action movie - you don't have much moment to rest your mind. Story is not that hard to follow but the dreams go within dreams and changes places/times. I'd recommend this for most people who like action, but for others who don't like to think much and like to see movies to relax - this won't be for you then.