For me it's usually around 1800 dpi. Smooth movement, minimal adjustments can be made comfortably.
But I've seen people playing FPS with 8000+
How the hell do people stay in control when 1cm mouse movement translates to half a screen movement or two complete character turnarounds? 360 no scope and all that bs wasn't even a thing until just a few years ago.
What's yours? How did you adapt if you are also one of those who use extremely high sensitivities?