The Ready State Virtual Mobility Coach is like having a virtual Kelly Starrett in your pocket.
I think going slightly below parallel is the top number 1 thing people say. Beginners are the ones who are most affected by this as its advertised by many. The excuse I bought into was that it will work your quads more so then hamstrings thus leading to muscle imbalance and knee pain. It is a lot less sexy to talk about working on motor control before you can go below parallel.