call to arms is indeed the only good choice you can make with a 5 sock bow. It's a decent bow and it can freak people out when you cast bo as a bow user though when it comes to killing speed it doesn't come close to the other big cannons.
It is used by some poison amazons to have a weapon that can be used for guided arrow and bo at the same time - that way you don't have to prebuff bo. Though again it will be better to prebuff and use faith for your guided arrows.
It's more a utility bow when used on a poison amazon then it is the top end choice.