The input is far worse then source in every way, although this is the game with the best of any i have played released in the past year. Still nowhere near as good as it should be, its not smooth like source engine in comparison. Its really hard to find engine specific info on this or Dirty Bomb for that matter, what are some of the things to do? Apart from disabled all accel and smoothing plus RawInputUpdateTest true every launch.
4770k + 970 and it barely runs over 144fps with the dirty minimum configs you see, still feels like its under 100 though.