The included Helicon can be used effectively in one pass. Depends on your needs.

If you expect to be able to customize the sound of a generated track to perfectly match a given voice, you will reach frustration. But if you realistically use it to generate harmonies as background vocals (note 'background' where nobody is scrutinizing them) it can be serviceable.

There are better tools out there (for $$), but being included for free it does a decent job at what it does.
One key 'tip' would be to learn how to use a MIDI track to control what each background vocal is singing; this allows you to then control if a male sings these notes, or a female .. and this aspect alone can make a huge difference in the results.

Make your sound your own!
.. I do not work here, but the benefits are still awesome