After a decade in which film-makers have strived for realism, an era in which even zombie and superhero movies have been praised for their verisimilitude, Salt does a complete 180 and goes for the sort of campy, balls-out hyper-reality that is such a rarity in 21st century cinema.
It's a completely preposterous plot, full of more holes than a gopher colony, but like The Expendables (only much better), it hearkens back to an age where that was sort of acceptable. No one should be in any doubt that it's a dumb popcorn film, but as long as you can accept it on those terms (and it establishes those early on), it's pretty fun.
As for Bourne, apart from the first film (saved by the ever-charming Franka Potente), that series was a completely overrated snoozefest... Gimme 24 any day!