My husband and I did a three night, four day "Live like a local" experience in Terelj National Park. It was not an easy experience. The conditions were less than sanitary, and it was tiring to constantly try to communicate and engage/connect with the families. It was totally worth the effort. We felt like it was pretty authentic, and we learned a lot and felt more connected to this beautiful country and people by the end of our short trip.
If you go in with appropriate expectations and an open mind and heart, I doubt you would be disappointed.