Talk:Siege Onager/@comment-200.29.229.42-20170203180918/@comment-31031245-20170203182332

It depends on whether you have enough resources to invest in the upgrade, without slowing down your economy severely. It should be considered, as they have 25 more damage, improved survivability and a better anti-building bonus.

Also, some siege civs benefit more from Siege Onagers than the rest, due to unique upgrades and bonuses; I personally recommend Siege Onagers for the Celts, Ethiopians and Koreans.