I have one. it is definitely for sunny days, according to oakley's site it has one of the lowest light transmission %'s of any of their lenses. though it isn't that dark looking from the outside and most of the time you can see my eyes.
i have the emerald iridium for the splices and it's an awesome lens. it's actually pretty mirrored and hard to see in from the outside. its great for sunny days and pretty solid in cloudy flat light conditions. definitely not the best for super stormy days. imo its a really interesting colored lens. golden greenish in the front and really blue from the sides. its a good one quiver lens.