Speed 1 world : You have 24 hours to break a siege => You can play this world if you don't have much time.
Speed 2/3 world : You have 12 hours to break the siege, you need to look at least twice/thrice the day your account => You can play this world if you're very active.
Morale active : Farming lower players isn't very effective for top players, so they won't get very far ahead => You can play this world if you don't have much time, you won't get too far behing the top players.
Morale inactive : Farming lower players is a key for ressources, and bp hunting is good, but you need to be really active to do it constantly with multiple cities. Best players will leave the oters way behind => You can play this world if you're very active.
That's how i see the different settings. That's good there's different kind.