I can see what the Directors tried to do... and that's the problem in a nutshell.
The movie mainly covers flashbacks to various time periods and as they overlap, you'll get more and more confused with the plot. That is exactly where they want you; for the big punch line.
Which is a let down...
Would have been a good movie as a stand alone but then again, might have been too complex given the confused timeline and the many characters. Being the third of the trilogy, I expected action, twists, depth and an overwhelming ending.
Only got the ending. :(