The Juwel fish tank aquarium heater should be seen as a premium product and as such, premium results should be seen when using this product. The reliability of the Juwel aquarium heater is very good and in many years of fish keeping I’m yet to have one fail on me. In fact i can safely say that one of the heaters I am using in my main aquarium was originally from my first ever fish tank purchased in 2006! So although you may be paying a slight premium for it, you know it is going to last the distance.
With regards to how well it actually works, well it heats the water and does it with a great deal of accuracy too. Once you set the temperature there is no concern about the thermostat failing on the unit or concern of having to check the tank temperature all the time as it will always remain stable.
Although this is not technically a “bullet-proof” or “indestructible” heater as many are advertised, it is certainly not a heater which you have to worry about a guppy swimming in to it and it smashing! It also has a cut off which means that when the water level drops it will switch off and not smash. This is very important if using it in an aquarium where you will be doing a lot of large water changes. After having this happen to me a couple of times with other heaters, i can assure you it is not fun trying to get glass from out of your fish tank.
Overall we don’t have a bad word to say about the Juwel fish tank aquarium heater. It comes with a high price tag but you get what you pay for and it’s more of a long term investment.