I have them for 2 months.
1. The lights turn on/off 2 seconds after pressing the button, which is unacceptable. (Unless it's because of my GEYER/Philips bulbs)
2. It makes a buzzing noise that others have noticed as well. However, I should mention that I have 2 in the adjacent room and they don't make a buzzing noise (I have swapped them, etc.). The difference is that there is wiring going from the dimmer to a further location for on-off. There, it doesn't make a buzzing noise before or after I put on-off.

Chinese in legrand format quite intense noise when dimming only at full power is tolerable for duration over time will show but seeing the quality I don't see it lasting

I would give it 5 stars if it didn't make an ANNOYING NOISE (buzzing) when adjusted to any intermediate position. It is (almost) silent only at full intensity. I have bought 6 dimmers for my house, and they all have this issue. I have now ordered a dimmer from Master, a Greek brand, for testing, priced at 21 euros. Hopefully, it will perform better than the heavily advertised Legrand...

UPDATE 3/12/20:
The Greek dimmer operates silently. The touch and click of the switch (the tactile experience) may not be like the Legrand, but functionally it performs much better. I would also like to note that a well-known electrical store, where I purchased them, recommended using only bulbs from "big brands" with Legrand. Although I consider such distinctions as excuses, I went and bought some Osram bulbs and replaced the Adeleq ones I had, and the switch made exactly the same noise.

I should note that the initial total load on the dimmer was 3x8.5Watt, clearly below the 45Watt limit for LED bulbs in this product as specified by the manufacturer (as I found out after purchase), and the Osram bulbs I bought were 7Watt.

An electrician who heard the noise said it is caused by the "thyristor" (so the problem seems to be design-related in the dimmer). And then they tell you Legrand...