First, there's the Attack bonus. It might not be as OSRS gold precise than the Godsword (163 fully equipped with it, 132 with the whip+defender set), but it's still an advantage over monsters' defense ratio. This lets you hit more frequently, when it comes to hunting trips. The second main advantage, is the strength bonus. You can inflict 6 damage points higher than other weapon (I believe Dharok’s Greataxe was the most powerful). Lastly, there's an additional 8 points prayer bonus.
It's all very appealing for hunting trips however, for combat in casual situations, mainly Slayer, the sword is less spectacular than you might imagine. It is more effective and more durable than the whip, but it is twice as slow. It is not the melee Dark Bow version. But, without the Black Mask, a super attack potion, and the Black Mask to compensate for OSRS gold the slower speed, I'd suggest another option. It's all about how large the monster (Black Demons, for example, Godsword's good there).