Although never have taken a yoga class, I am more interested as I know how tight and inflexible I am...just doing my own version of deep poses has helped me in my athletic endeavors. Health, flexibility and reduced risk of injury is more my focus in life now. If it works for you, then it works.
I remember reading this a while back too....as you may see more ageing athletes turn to less destructive training such as yoga...or how TO now talks about all his band only training (of course he is selling them too....but he has been doing it for a while and credits some of his career longevity to it). Keep in mind they had a good base of strength and fitness to begin with though.