There are really only a few times that you're going to need a Ranged Basic Attack (RBA). That would be when you're granted an attack from a leader character. There are certain feats and other abilities that affect ranged basic attacks, but this power would not qualify for those as it doesn't read "Can be used as a Ranged Basic Attack" and is instead used itself when you would make one.
So if you have a Shaman, Warlord or Bard who will be granting attacks in your party, this might be a good choice. But look at your other party members. Most likely you've got a striker or two and a defender. Those guys are going to be getting those granted attacks way more often than you will. It's probably not worth it to invest in that as your bonus at-will.
Something else to consider: as of Essentials, the human can take the encounter power Heroic Effort instead of the bonus at-will. This can be a nice little "failed my save...No I didn't" power or can make a missed attack a hit. It's worth looking at closely before you grab that unaugmentable third at-will.