Here's a question- which I could go and answer myself at home later; if you record something with NR on and playback with it off, does the material suffer beyond what would have happened if you didn't use it all...
Yes, in that you are playing back something that has had its high end artificially boosted by the initial Dolby encode, that would be reduced if properly Dolby decoded. Without any Dolby at the start, the high boost would not be there. Dolby off at record and playback is fine if that's your thing. But Dolby on for record and off for playback is like turning up the treble. People like it but it isn't as accurate.