I have ranco's and herpstat's. I have had ranco's fail to turn back on due to excessive power outages where I live (I have read this is a common problem, I think it was on a beer forum or something like that). The other thing I really do not like about the on-off style thermostats is the constant clicking when the thermo kicks on and off. I have switched to using all herpstats at this time because of the worry of a ranco failing and not turning back on due to a power outage and I also hated the clicking sound. I now have my ranco's set aside in case something goes wrong with any of my herpstats I have back ups until I can replace it with a new herpstat.