Unless the Errata changed again, there is a -30 penalty to Move Silent when character is in Armor with a Defense Value of 7 or higher. I know, StormTrooper or Kasrkin Carapace isn't a 7, unless it's Good or Best qualities. We know at Good quailty it's only 7 on the first hit of the round and at Best quality it's 7 and half the weight.
On a pure number basis, BQ/GQ ST/K Carapace thus would inflict the -30. Am I being way too strict in my interpretation since why would a better model impose a penalty the base model would not?