I am not a Chism fan, and hope I am wrong. I understand the difference between quickness and speed, Chism is quick, but not fast. His kickoff returns were painful to watch.
What I do not see acknowledged in Chism threads is that if a player can not run past a defender because they are too slow (like Chism), it is much easier for the defender to crowd the offensive player to limit their quick twitch separation. Although Edelman, Welker, and even C Kupp, were not fast guys, Chism is the slowest of them all.
I have also seen it argued that only the 10 yard split is important for a slot receiver. Although there is some truth to that, if the defender only has to worry about 10 yards the defensive assignment is much easier. For example, I think M Jones can easily shut down Chism, and that is the type of defender Chism will have to routinely defeat.
For the 1000 Chism fans on PatsFans, please don't read my post and think I am attacking your first born child because I am not a Chism fan.