Gray, black, and dark smoke tints are purpose-built for bright, sunny days on the mountain. They reduce overall brightness without distorting colors, so you see the snow and terrain exactly as they appear. This makes them a great choice for bluebird days, spring skiing in intense sun, or high-altitude glacier skiing where UV exposure is extreme.
The big advantage of neutral tints is true color reproduction and reduced eye fatigue during long days in harsh sun. However, they offer very little contrast enhancement, which means they struggle in flat light or overcast conditions. If you're skiing on a cloudy day with gray lenses, terrain features can become nearly invisible.
If you mostly ski sunny destinations or want a dedicated bright-condition lens to swap into, gray or dark smoke is an excellent choice. Just don't rely on it as your only lens if you regularly encounter variable weather.