I had to look it up. Sounds similar to a mentor concept, but something about it seems off.
For one thing it is not a Christian based idea, the site i looked up talks about this involving other religions as well. Looking through Google it seems most of the references are not Christian based.
I don't know a lot about it, but even the term 'spiritual director' sent up red flags for me. Personally, it is not something i would involved myself in. But, as i said, this is a cursory take on things. So i don't have a full understanding of it, though i have no desire to learn more either as i still have a funny feeling about it.
Mentors and such can be a good idea, to a degree, but caution needs to be used as we are not to follow the guidance of others, but of God. It is so easy to look to a person that we raise up in our minds. An ex of mine did this years ago. She became so reliant on her 'mentor' that she would go to this woman for guidance and direction in her life, not God.
Years later as we spoke about it she realized how damaging her reliance on this woman became to her, both at the time it took place, as well as the years to come.