We use REX daily, but our initial training was from PTC University. It was a descent training class, but REX is not that supported when compared to other modules. It's too bad because many companies use 3D Scanning Technology in house and PTC is not providing the support for those who invested in REX. We are looking at going with a different Reverse Engineering application that works with Pro/E for this very reason. REX is complicated enough, where it would be hard for me to create a general training video. If you have a particular question, I can try to answer it. The only way to get a full training that I know about is using PTC University.