I have come to believe that there is no such thing as a reliable brand tank heater. Every brand i have tried I have experienced some failures with and in two cases a heater stuck full on and wiped out a lot of fish. In the tank that went to 104F the L450s had hundered down in caves and lived and acctually spawned a few weeks later. In the second incident the tank hit 120F and wiped out 10 breeding RB line 236 and about 25 of their fry. Fortunately, I had another 45 offspring from which I put together another breeding group.
The result of these fiascos drove me to buy heater controllers for any of my tanks with very expensive fish in them. Also those two incidents above involved different brands of heaters. Most of the failure tend to be the heater stops worked. The next most common issue is they get inaccurate. This is a thermostat issue rather than the heating unit failing and it can happen in either direction- too warm or too cool.
Of all the heaters brands I have owned the one I favor is the Hydor inline heater. I have them on the three tanks where I use canister filters. It took almost 20 years for the first one to fail. I had a replacement on the shelf for years.