I have the mouse and I enjoy it a lot. I have set it at the default 1k right now.
I read a youtube comment saying that there have been reports of the 2k and 4k modes not working properly, so you should either go with the 1k or 8k.
To be honest I'm not interested in using the 8k mode, it just eats up battery way too fast. I have a 300hz monitor arriving today and was ready to go up to 2k or maybe even 4k, but I'm now not too sure if I even should.
Anybody have more info on this?