It all depends on what you like to play. I NEVER play 1on1, seldom 2on2 and mostly 4on4. My sens might not be the best for, say, dm4 1on1, but it's superb for lower speed 4on4.

The other thing is, that you have roughly 2 different ways to aim: Aiming mostly with strafe, or aiming with the mouse. Some players like to have very little mouse movement, and instead kinda "lock" the target by strafing. If you know what i mean. The others ofc do use strafing, but they mostly rely on fast mouse aiming. And now I'm speaking mostly 4on4-wise (lots of sg, ssg, sng - lots of predicting and spamming).

ps. Im not trying to say which is the ultimate best (which is impossible), I'm just stating my arguments.