I recall the red light was quite handy when flying the Twotter. The instruments lights could be dimmed to the right amount, but for doing anything else that looking at the instruments the red light fell in just fine. Nowadays on the bus I don't think of it as that necessary as it was on the Otter. The screens can be dimmed to the right amount and the light on the little coffee tray it's good enough to do everything else. If anything it's the newer LED tray lights that it's a bit annoying to use because they're so bright. I kinda like the conventional lights a bit better for night flying.
FWIW, in a clear/bright night, the night vision does serve me up a bit to combine my eye analysis with the radar to avoid an isolated CB or something like that. Sometimes it's not strong enough to get picked up by the radar but one can see it's shape and you can take a guess of how to avoid for mere turbulence-avoidance purposes