Moray is pathetically quiet, even though he has massive NFC traits, and when he does meow, it's always almost an apology.
The Gurlies were very vocal up until about 6 weeks ago when they got the key to the cat flap and began going out on their own. Now, they don't vocalize nearly half so much. Barley will still give little trills of pleasure when you give her a good back rub, and Malt still chirrups softly if Moray or Barley come in from outside, but it's a lot quieter than it was in our house. I miss Barley's battle cries as she flew up and down the stairs in an excess of energy!