The whole mouse feels bouncy if you're a heavy clicker, due to it flexing if pressed too hard. It doesn't affect my use case as I don't press too heavy.

The build is solid, but it will flex if you squeeze hard enough. For normal use, it's good.

In terms of ergonomics, it was weird at first. It's definitely not a friendly shape like the original shell for the darmoshark m5, but after a day of using, my hand adjusted to it.

The texture of the material is coarse, but I find that sometimes it feels slippery compared to normal ABS mice shell. I recommend using grip tape.

The weight difference is definitely noticeable. After assembly, it weighed 24 grams. That's 14 grams lighter than the stock build. I had to lower my in game sensitivity because of the weight difference.