The material room is what makes P5 enjoyable for me. Instead of flat image files for textures, you can layer them with effects (such as the Real Skin shader). If you've ever used VUE, I find the material building similar in concept, though the interface is substantially different. I had no trouble moving from PP to P5. Multiple runtimes helps a lot with organization. Don't let it overwhelm you. Just like any other task that seems so large you have trouble figuring out where to start, it's a lot easier than you think once you actually dig in. Just do one small step at a time. If you decide to reinstall some items for their P5 content, do it one item at a time, and take the time to go into P5 and play with it for a bit before installing the next one. The ONE thing I've found impossible to deal with in P5 is Victoria3, but that's more to do with how DAZ set up all of her Pose folders with dozens of !DAZ folders instead of any kind of organization. However, that's a problem with PP as well.... it's just that it started to irk me since P5 because I know now that P5 would allow them to organize it more elegantly than how they have it.