From what I understand, if a Herpstat fails, it will fail off, meaning that it will provide no heat when it fails. Dimmers and some thermostats could fail on, meaning that it will give full power and be a burn hazard for the snake if not a fire hazard. For that reason alone, I am going to go for a Herpstat. My only question is do I go for the 1 or the 2? I'll open a new thread for that when I get closer to getting one.