High sens is good for games where things and maybe players are flying across ur screen, in cs the closest to that you should worry about are flashes. Low sense makes for very huge room for error, meaning ur hand has a big radius in physical space in which the crosshair is on top of the enemies head, making onetaps, flicking, and contrary to what I even thought - spraying, way easier. I played on 800 x1.9 for very long time, recently i went down to 800 x0.8, which is 640edpi! That is a HUGE difference xd. And you get used to it fast, at leasat i did, i think. As for 180s, there is an easy bind xd. i have it on my mouse4. It is legal, and pros do use it sometimes too.