when i squat i believe in squatting to the rule book depth, of hip joint parallel to your knee, though i usually over shoot it. some of those spf squats did look high, but i just worry about myself.
When i did the 550 in the last pro/am i have no idea how deep i actually went (no video of it) I had somebody call my depth when i hit parallel and then i went up, i really was just worried about keeping my air in me and not passing out, as i was getting squeezed pretty bad the deeper i went.
for comparison this is how deep i squat raw (my 468lbs at 165), but this was at a NASA competition
sorry for the blurry camera didnt want to focus.