I spent one month at Ananda Yoga Center in January 2014 completing a residential teacher training course. I was already certified as a teacher in America and was looking to expand my personal practice. I wasn't interested in a touristy, spa-like center but was looking for something more traditional and authentic. I found that experience with Sivagiri at Ananda. By the end of one month, I had learned many new partner yoga asanas, was able to teach yoga nidra, had been taught how to play several chants on the harmonium, and was able to cook multiple Nepali dishes. Sivagiri's extended family are all involved in the center. Several have spent many years in India studying Satyananda Yoga. Raj is a very knowledgeable, hands-on asana instructor. Everyone is very experienced at mantra/chanting. And the veg meals are always fresh and delicious!
Upon completion of my course, Sivagiri invited me to accompany him and several of his Kathmandu yoga friends to the Bihar School of Yoga in Munger, India for a four day program. I would never have had this opportunity if not for my time at Ananda. Morning mantra and evening kirtan at Ananda prepared me to participate in the chanting while at Bihar. And I felt very comfortable overall with the Satyananda philosophy.
I had a great overall experience with Ananda, but I can understand how it might not be for everyone. It would definitely help your experience if you already have an understanding of yoga and are a motivated, self-starter. Also, some westerners might find the amenities very simple - the rooms can be cold during the winter, the power is off many hours a day (like all of Nepal), the water pressure could be stronger, and the wi-fi is finicky.
I am again visiting Ananda right now and it feels good to be welcomed back home by close friends.