Logitech mouses

It's not that much about practice if your mwheel is unstable. By that, I mean that with the same scroll you get different results every time. I think G402 (newer products) have this issue, while fykseN claims it's stable for him with his older piece. It also might depend on finger and direction of scrolling (pointing finger and mwheelup for me) - G400 had the best results by far.
Recently I tried G502, which had pretty stable mwheel and my bhop just felt good again. However, G502 is not a mouse for KZ because of it's mwheel physical properties (heavy, carrying too much energy that vibrates the whole mouse) and now I am looking for something else with stable mwheel.

I am not a G402 user but I have the same feeling switching to a new mouse. I used g102 for the past few years and it works pretty well for pretty much everything except double or multiple countjump( might because the wheel is way too hard), and I got a razor basilisk recently, and my speed or strafe just not as good as before. What I want to say is that it might takes you a period of time to get used to the new mouse caus no matter how good the new one is, your old mouse has been with you for a long time and you just cannot have as good control of the motion as using the familiar one, muscle has memory and for the most part it affects subtle things.

try cs in windowed mode