You don't engage enemies at a long enough range in F3 or F:NV for the suppression of a supersonic round to be of particularly high value. The "realistic" supersonic crack of a suppressed .308 round is still pretty loud. That said, a quality suppressor firing subsonic ammunition will often only generate sound from the cycling of the action.
Since the engine only classifies weapons as "loud", "normal", and "silent", it doesn't leave much room for gradation.
I think I was being slightly obnoxious, but thanks for the response. Hollywood silencers are a minor pet peeve of mine. One I can ignore, especially since the general audience probably come to expect the silent silencer.
The range point is a good one I never even thought about. I don't expect most games operate at the kind of ranges for that.