Arrow Blow and double shot when they are maxed in Maplestory, they have the same damage. But before you can add arrow blow, you have to add double shot. Only choose one of them. The extra SP goes to focus.
Pros of Arrow Blow Use lesser mp (maple story gold). Use only 1arrow at the same time save money. Making the highest damage is high as possible.
Cons of Arrow Blow -If the damage is low, there is no hope of getting that damage high. Most of the time the damage is quite low.
Pros of Double Shot - If the damage is low, the other arrow may have a higher damage. The damgage are usually high.
Cons of Double Shot - Use 2arrow at a time at the same time waste money. Use more mp. If the 1st arrow damage is high, the other arrow may have a lower damage.