Official comment
"Faders also gitter up and down a little bit whenever I move them too fast."
That sounds like you haven't applied the last firmware:
Ver.1.06 (30 November, 2015 Update)
FIXED - Multiple Channel Faders worked incorrectly when used at the same time.
Please ensure you've put the SX2 into firmware update mode before running the updater:
Turn on the power of DDJ-SX2 while pressing the [SHIFT] button and the [SYNC] button on the LEFT deck, and ensure the Level meter LEDs flash before releasing your finger from the these buttons.
If you still have issues, please try another USB cable or port on your computer (failing that; another computer).
