IMHO you should spend a little more money and buy something with a solid-state thermostat. The bi-metallic thermostat has a much greater chance of failure--especially a "stuck-on" failure.
Ebo-Jager. I've got about 6, and have never had one fail, including the 5 year old one I've got in my water storage system. We sell them at the shop I work at, and have never had a return while I was on duty.
Ebo all the way, I have never had one fail on me and they heat the water at a constant temp every time. If you are using it for a small tank marinedepot.com has a 100 w on sale now.
Does anyone use the Azoo heater controller w/ glass heater that petwarehouse sells? Ive only had mine for a short time but I think its the greatest thing ever, a little spendy for a heater but it comes with an actual temp controller with probe but I never hear anyone talk about them.