Wikipedia states that there was National Treasure edition that included 9 more DLCs than Game of the Century Edition. In the GOG description there are only 5 DLC and I don't see Enter the Dominatrix and How the Sints Save Christmas that are listed in Steam. So I became doubtful are there really all DLCs included or "meh... there is a lot so let's call it complete collection"?
And by 5 mentioned in the description, you mean this? The American (Fever) Dream
– Play as the President of the United States in a story that spans countries, space, and time. Saints Row IV is to Saints Row: The Third what Saints Row: The Third is to Do The Right Thing. You’re not ready. Super Hero-in-Chief
– Leap over buildings. Kill people with your mind. Run through tanks. Those are some of the most mundane powers you will wield in your quest to stop an alien menace hell-bent on destroying the Earth. Alien Toys of Destruction
– Wield an impressive array of alien vehicles and weapons… FOR SCIENCE! Custom Weapons, Custom Mayhem
– You’ve customized your character. You’ve customized your clothes. Now you can complete the look with our all new weapon customization system. Turn traditional weapons into exotic conversation pieces! Dynamic Duo
– Seamless drop-in, drop-out co-op, a Saints Row standard, improved. The only thing better than one malicious super-powered President is two.