From what I understand about racks, high-quality simply means it's not been made with shoddy workmanship and isn't going to collapse within a few years, as well as any wiring already being professionally done for the rack. PVC also retains heat and humidity pretty well, and is lighter than wooden racks. However, UTHs only do so much, and having ambient temps as low as 60-70F for ball pythons is a no-go. The temps need to at least be 75F, more ideally 79F, as the UTHs only warms a surface and not ambient air.