I have been a yoga practitioner for over 10 years and am still practicing and will always practice. I have seen various types or forms of yoga blooming. This form of practice has become so popular that zen like studios are sprouting up all over the world. Classes are full and many. Its all about the ambiance and the numbers. Its become a major business, its an industry on its own!
My impressions are that most classes are geared to the young crowd (30s and below). The schedules are filled with power, bikram, viniyoga and many others. The designs or sequences of the classes are great and filled with intricate asanas or poses. Many could get into them and were ready for the next level or stage.
I would walk out of these classes feeling like I had a great workout. My muscles would be challenged but something was missing. There was a void. I did not feel complete. So much attention and focus is placed on the Asana that the very spirit of this practice is lost.Yoga is wonderful for the joints, flexibility and spine, but what use is the body if the mind and spirit are under nourished.
To me yoga is the practice of connecting the body, fluctuations of the mind and the rhythm of the breath to become one. Learning to be more aware of our thoughts, actions or speech. To avoid being judgmental on others. Being in tune with one's feelings and experiences. These are the treasures of Yoga.
Yoga is so much more than postures (only 2% of yoga is focused on asanas in the Yoga Tradition) its about how we interact with others or how we incorporate it into our daily practices. Yoga is a practice of understanding the inner journey of the self.
The above are just my opinions!