barely good for its price
the spot that shows the material (metal in my case) also requires some luck to find
It does NOT have instructions in Greek (and the instructions it does have are very brief)

For its price and for amateur use, it is just fine. It needs calibration at first to work properly. You should remove it from any wood, cable, or metal and press the button for the selection of the type of object you want it to detect repeatedly until you hear the sound, then test it on a corresponding surface to see if it works and it is ready for use!

After an unfortunate incident where we hit a power cable while drilling for a curtain rod, I decided not to take any chances with the rest and to go for a detector instead. Unfortunately, it seemed to show random readings, making it impossible to rely on its measurements, especially for something as dangerous as hitting a power cable. In the end, the electrician showed us how to find it ourselves using the old traditional method of tapping on the wall. 50€ wasted (I bought it during a time when it was somewhat scarce).

It detects anything. Not helpful at all. It hits the metal more accurately but still with a large deviation. For cables with a load, it really shows completely different things from reality. For example, I touch it to wood and it shows that it detects a load. For wood, to catch it, I have to press the tool quite hard against the wood, and it doesn't catch on all types of wood.

It does what it promises, that is, it finds metal inside the wall, pipes with water, and cables with electricity. I didn't need to use it for any other material for now.

I have no experience with any other machine, but I tested it on the wall where there was a cable for the socket, it hit the alarm and the light turned on