I use that same controller. It's been running on my tank for 3 plus years. Works very well and is extremely accurate. You can calibrate it to get it within a half of a degree if I remember correctly. I checked it a few times over the years, and it hasn't changed. I agree about making sure your using good working condition heaters, and checking them once a year.
I have an inkbird. I shut it off bc the temp reading was off after two years. I was wondering why it seemed like the tank was running hotter than usual this year and two thermometers showed it was off.
I didn't realize I could calibrate it: I need to do that sometime.
I'm fortunate in that my tank maintains it's temperature without the heaters. The filters and powerhead keep the tank around where I want the temperature in the winter (plus being on the top floor of a condo structure means is warmer here even if I keep the heat off. With my central heat off, I'll be around 70-72 in the winter.)
The tank gets hotter than I'd like in the summer but a cheap fan keeps the tank cool. It's too bad I can't use the inkbird to turn this fan on when needed (if you shut power off to the fan, need to use the physical button to turn it back on).
Anyway, it's good to know my inkbird still can work if I calibrate the temperature. Maybe I'll move it to one of my QT tanks .