One Reddit user (u/CrusaderKing107) summarized it perfectly:
: The Director's Cut adds approximately 45 minutes of footage. This includes a significant subplot involving Sibylla’s son, which clarifies her motivations and provides a more cohesive emotional arc. kingdom of heaven isaidub better
The 2005 Ridley Scott epic, Kingdom of Heaven , is widely considered a much better film—and a more detailed story—when viewed as the Director's Cut Kingdom of Heaven