I have 4 Hydrofarm thermostats, and 1 Herpstat Basic. Two of the Hydrofarms have been running since 2012 with no problems. I have 2 on 1 cage, one controls a CHE that is for the ambient temp in the cage, and the other controls a piece of Flexwatt for belly heat on the hot side of the cage.
The only draw back with the Hydrofarms, is that they are Off/On controls, so they shut off at 2 degrees higher than the set point, and turn back on at 2 degrees below the set point. But they have actually kept pretty accurate temps for almost 3 years now. So I guess they were worth the $30 each .
And they do have a safety shut off that activates at 108 degrees.