This is a remarkable film and, in my experience, an original one. Reznik's painfully wasting body and sleepless existence is an excellent allegory for the withering of his self esteem and the nagging conscience that would not allow him to rest, respectively. It reminded me of The Picture of Dorian Gray and of Mark Twain's delightful essay The Facts Concerning the Recent Carnival of Crime in Conneticut though it probably has more lineage than that.
Thankfully I watched the film without thinking too hard about it meaning that, unlike others in attendance, I was blindsided by the twist until the conclusion and so most probably enjoyed it more than my fellow viewers enjoyed their smugness at having worked it out "in the first twenty minutes".
Though the plot is somewhat skeletal and hopeless (rather like Reznik) the film has a message worth selling to anyone in posession of a conscience - psychopaths & sociopaths need not apply. Bale's performance is very good though his appearance is distressing and his apparent desire to drop to 100lb skirts frighteningly close to the mindset of an anorexic. Indeed his physical sacrifice for the role was, for me, the absolute limit an actor should push for his art.
Bale has constantly (and pleasantly) surprised me ever since American Psycho and as he ages I'm sure we can expect to see his range given more room to project his talent.
A disturbing but interesting work.