I bought this specific mouse to test if it fits the shape of an ergonomic mouse, as I didn't have one in the past. My previous mouse was the Logitech MX Master 2, which for me is perhaps the best mouse available, but it broke and I didn't want to spend 100 euros on a mouse again :(
Now let's move on to the observations:
After two weeks, I couldn't get used to it and gave it to my son. This is not, of course, a problem with the mouse, but rather with my age :D However, if you haven't used an ergonomic mouse in the past, it's a good idea to go to a store and try it first to see if it suits you.
-In terms of functionality, it fills your hand, and the left and right clicks are satisfactory but not silent. The surface has a good feel in the hand.
-The problem lies in the navigation buttons (a basic requirement for me) which are not ergonomically placed, at least for my hand. You have to stretch your thumb to reach the front button, and the back button is slightly higher than it should be. In other words, the buttons are not in a position where you can press them without thinking.
-I found it excessively light, resulting in a lack of stability in programs that require precision in movements. Of course, I'm coming from the Logitech MX Master, which is perhaps the most "well-balanced" mouse available, so it could be that.
-It does not have programmable buttons or accompanying software. If you want to program the buttons, you will need to install a program like X-Mouse or Volumouse.
-Although it changes DPI, there is no way to know what DPI you have except by pressing the button and seeing the cursor sensitivity, which is a bit blind.
Nevertheless, the mouse is of good quality, and for someone who is accustomed to the shape, it will satisfy them. I see that there are identical ones available in the market, just with a different brand, at various prices, so they are likely all made in the same factory in China. Just try one first to make sure the shape suits you.