I don't think that it is active in this patch.
Have you pick it up from the skill descriptions on this side. If that's your only documentation, them I'm afraid that it will be something from the 1.9 patch.
Assuming that it will be the same raduis as strafe - that used to have the same feature - then it should be quite big. I've heard strories of people shooting over 50 arrows by partying up with necromancers, and as you know, skeletons don't stay close to an amazon.
P.S. why not test it, and let us know. Go to an act boss, attack and count the number of hits. Repeat with decoy - works too - close to you.