Having correct posture is very important if you want to be a consistent golfer. It's just as important as any other element of the PPGS Master Setup position.
The key to having perfect posture is being in an athletically ready position with actively engaged muscles. The setup determines the motion, so your setup better be perfect!
As we age, our bodies change and we aren't physically capable of doing the same things we were able to do 20 or 30 years ago. But, what we give up in power we can gain in accuracy. It all starts with a good setup.