It seems like there are many situations where one could choose whether to use $asArray or $asObject, in the same situation. You could get away with us
The latest version of angularfire 1.0.0 uses new $firebaseArray and $firebaseObject services that replace $asArray and $asObject when accessing collections or objects.
If you are using the latest version, you should convert $asObject and $asArray to the new services.
var arr = $firebase(new Firebase(URL)).$asArray;
var obj = $firebase(new Firebase(URL)).$asObject;
becomes
var arr = $firebaseArray(new Firebase(URL));
var obj = $firebaseObject(new Firebase(URL));
Additional information is available at AngularFire Documentation