Not all of us even have the ability to use it. As a PS4 player, I got no chance of seeing my own numbers whatsoever. Whenever I want to test out rotations I am forced to bother friends who are on PC.
As I'm raiding I always try to improve my skill and even if another rotation is just marginally better, knowing that and optimising is what I'm having fun doing in this game. Would be nice if I could do that on my own and with ingame methods.