Well I have, even with it on 50.
My last game Todd Gurley broke free on a long run on the first play of the game. my 72 speed 300lb DT comes from no where and chases him down from behind 50 yards downfield. its an absolute joke.
That was the last straw for me, I've lowered it to 30 now. Making the players have very little speed difference is good for game balance vs the CPU but its not good for realism - which is what matters more to me.