Well, usually people buy these thermometers for the convenience they offer when taking measurements on small children. Especially babies who don't sit still with a thermometer under their armpit and as a parent you are anxious and want to measure the temperature every half an hour...
After many tests, I concluded that it can have accuracy only under certain conditions. The distance from the forehead must be specific, you must have your hand relatively still, and it must be in a specific spot on the forehead (right in the center and slightly lower).
If you manage to do that, the deviation from a mercury thermometer will be small. Otherwise, the deviation will be quite large. This means that it is easy to take measurements on adults and yourself, but difficult on a baby, unless they are sleeping.
So, to avoid excessive expectations from readers, from my own experience, the thermometer only works under the above conditions.
In the positives, I can include that it is very easy to use, high quality, and quiet so the child doesn't wake up while taking measurements.
In general, I understood that the other models have the same disadvantages. I don't know if there is any model, even an expensive one, that provides very accurate measurements without much attention from the user.
So, to summarize, I use it constantly but when the child has a fever, I also use an armpit thermometer. When there is no fever and it feels right with my hand, then I also use this thermometer for confirmation. When I use it, I also take several measurements for certainty. When there are no significant deviations, then I accept the measurement as true.
Update:
After a year and a half of use, today is the third time I am changing the batteries. By the way, I always use the best alkaline batteries. For some reason, when I haven't used it for more than a month, the thermometer consumes the batteries and at the moment I need it, I have to change them. For this reason, I lowered another star, so now my rating is two stars.
Overall, I do not recommend it.