When I first started keeping snakes I used heat cable. In my experience it runs extremely hot unregulated which in the case of a thermostat malfunction could be disastrous. I had AP cages and the heat cable heating was very uneven. Extremely hot right at the area where the heat cable was routered in and then not close to warm enough 2 inches away. Mark and Ali do a great job and if they say there have been no incidents, I believe them. For me, heat cable will never be an option. Radiant heat panels are an excellent choice for caging and Rich has done a great job with his. I am about to pick up two of them for my boa cages.
Jamie