To my understanding , the x17 has the 8000hz polling rate while the x20 is wireless and sticks with the 1000hz polling rate, so if you're interested in trying out the 8khz polling rate get the x17, I have one on the way and looking forward to seeing how it stacks against my g502
Also, I would like to add that it does have it's own software for the mouse, and it remains to be seen if it will sync up to my 3090 ftw3 ultra as I lt uses px1 software.