How to get the user id from createUser() in the newest firebase release

Question

so it seems that i cant directly get the user.uid upon creating a user or its not implemented in the documents. I have tried this chunk of code below to no avail as authdata returns as empty. is there a workaround?

NOTE: wherever you see Authentication its a factory that returns the working code to create a user or login a user using createUser() or $authWithPassword accordingly.

$scope.register = function (){ 
    Authentication.register($scope.user)
        .then(function(user){

            var ref =  new Firebase (FIREBASE_URL + 'users');
            var firebaseUsers = $firebaseAuth(ref);

            ref.$authWithPassword({
                email: $scope.user.email,
                password: $scope.user.password
            })
            .then(function(authData){

                var userInfo = {

                regUser: authData.uid,
                date: Firebase.ServerValue.TIMESTAMP,
                firstname: $scope.user.firstname,
                lastname: $scope.user.lastname,
                email: $scope.user.email
                }

            firebaseUsers.$set(regUser,userInfo);

            });     

            Authentication.login($scope.user);                                          
        })
        .then(function(user){
            $timeout(function(){
                $location.path('/meetings');
            }, 2000);
        })
        .catch(function(error){
            $scope.message = error.toString();
        });
} //register

i have seen this response but doesnt seem to apply using it with angularfire

ref.createUser({
 email: '...',
 password: '...'
}, function(err, user) {
 if (!err) {
   console.log('User created with id', user.uid);
  }
});

any examples that work with angular version?