It's a game changer, especially if you sit all day (desk or stand). The spiritual part did nothing for me, but some enjoy it. I just enjoy the flexibility. After a year of classes, I had learned enough to do it on my own and it's a big part of my daily workout.

Side note- I had some back problems 15 years ago when I first started sitting at a desk all day. Dr sent me to PT because it was muscular. I recently found the PT sheets and it was all yoga.