Fwiw their definitely WAS x-factor (bort at one point fixed an "error" that caused some players to have 0 or negative weight in speed calculations). I imagine this was the x-factor put in intentionally, but when speedtests exposed bort had to fix the "error".
As far as current x-factor, it still feels like it exists and perception is reality. Still with the number of variables in builds, gameplans, opposing builds, opposing gameplans, you could rationalize it into x-factor not existing. All I know is sometimes I see players that are clearly dominant while players with nearly identical builds perform badly. *shrugs*