Well, I loved mine until yesterday when I discovered it wasn't working and it was 70 degrees in my tank. I have the 200w version for 1/2" hose hooked up to an Eheim canister filter. I bought both at the same time about 3 years ago. The filter works great. Only the light works on the heater.
And that's the problem. On the typical HOB
heater, you can touch it and feel it get warm. You can't do that with the inline heaters. I put a spare heater in the tank and I'll be shopping for a replacement but I'm not sure it will be another inline.