What are the main differences?
I understand that Olympoian citizens are individually more impressive, they are true immortals, such as why Zeus looks like he is in his physical prime, whilst Odin looks older.
However, Asgard appears to have more realms and has more of a warrior culture.
Most of them seem to be just nameless or faceless background characters who are trotted out to fight and or die during battles. At least with the Olympians, you have Zeus, Ares, Hercules, Pluto, and isn't Neptune one as well? On the other hand, Odin does have the Destroyer armor, so.