This is my humble perspective regarding Modern Postural Yoga and its role in the awakening of consciousness.
I do believe that there are many benefits from this practice, the most tangible ones are perceived in terms of physical wellbeing: the body becomes lighter and radiant, the digestion works better, one rests deeper, there is more flexibility and strength in the body, the breath becomes longer and softer, the integrity of the body becomes evident. Though negative effects can also happen when practice is not done in an appropriate way for a particular individual (yes, bio-individuality also applies to physical practice, and there is no recipe which will fit all… this is a whole other subject which I am not discussing today).
There are also many subtle benefits, some easier to perceive than others, in the emotional/mental and energetic level. The connection with the body and the breath and the single point focus create an opportunity for the practitioner to become more aware, to start to awaken from ones preconditioned way of living and move towards that which is ones true nature. Most of the time, this process is not comfortable at all, it is actually painful to start looking at our darkness and stored emotions from past experiences, our tendencies and limiting beliefs. But here is where I have a big disagreement with the approach that Yoga (as āsana only) will take you to the awakened state. It is very easy to get lost in misconceptions in our modern appropriation of yoga.
For instance, backbends allow us to work on our nervous system, awakening the energy from our spine. They feel amazing and requiere lots of control of the breath and awareness of how to relax the Psoas (or a very flexible spine). By practicing with conscious alignment one can create a deeper space in the body through the practice of backbendings, and so a healthier spine, a deeper and more controlled breath and as a result a healthier nervous system which will impact every other system in the body from the digestive to the endocrine.
But there is no awakening happening by “achieving” a deep backbend, a difficult transition, a leg behind the head, a hand stand, or any beautiful shape, those are tools, as is the practice of Surya Namaskar. It is not about having the best tool, but about how we use that tool. Postural yoga is a tool for one to develop that pureness of the physical and energetic body, the focus and awareness, and to start moving the subtle body. But one has to decide to use the tool with a purpose.
My opinion is that for one to awaken, there is a whole universe of additional work, which is even more essential in this yogic path: the work of observation and direct experience. Otherwise, the tools become merely a decoration. Like when we have a beautiful Tibetan bowl which remains on our altar, for months, without being touched, decorating a section of the house. There is nothing wrong with this, but there will be no effect on our cells until one decides to play it and experience its vibrations.
To be more clear, what I mean is that I could keep working on my backbends for years and maybe I would be able to grab my heels in a drop back with no difficulty, or maybe I will touch my nose with my toes while in Vrschikasana, but this will not guaranty any spiritual evolution, I could achieve all of those postures and still be mean with people I don’t like, aggressive when driving, dishonest with people around me, not care about our planet’s preservation and being engaged in a life of pride and attachment.
So, one should do the practice that feels good for oneself, which can definitely help to clear the glass, but then one has to engage with the higher practice, which is the practice of living with consciousness and a higher purpose, for the benefit of all beings.