Joe,
I worked at Tumble Creek one summer back in 2010. I was on the maintenance staff helping get the course ready for the summer season for a couple weeks before I was in the shop. When we would go out and rake the bunkers we were always told to rake the sand up the faces, you have to do this on big flash bunkers with big sand faces. When you are constantly pushing all the sand up on the face, you are putting more sand on the face than down in the bottom. So what would happen, is if you hit the ball in the face it would always plug, and then if it was down in the bottom, you had a hardpan lie with little sand. Trust me one round I had about 5 plugged lies in the bunker faces, where you just hack and hope.
I personally think everyone else needs to adopt the Australian method of how to maintain bunkers.