Good and bad at the same time
I like the shape of the mouse, the grip and the placement of the buttons, but that's about it.
The software is a horror, and I've fired it and replaced it with the old software (Logitech Gaming Software), which offers the same possibilities, but is much more functional.
The overall quality of the mouse seems shaky to me.
The cable is very thin and not braided (whereas other discount brands have braided cables), and the plastics are of poor quality.
The weights were of no use to me, it's heavy enough as it is.
And finally, the thumbwheel is very noisy and slippery.
In short, I'm rather disappointed, given that I bought it to replace a cheap SoG with which I was extremely satisfied (5/5), especially as it lasted 4 years despite costing me 30 quid...