Ambre Nuit was utterly unique when it was released. Sparkling yet powdery florals on a bed of woody resinous amber. Absolutely unisex, a classy perfume with soft sillage that ends up being very versatile as a result of the almost fresh nature of the amber.
Having not tried Ambre Nuit, I bought 40 Knots which I think is inferior in every way save performance. The florals are more defined, the resinous presence is more apparent. But to be fair, Ambre Nuit needed a bit of an upgrade to its performance that 40 Knots provides. Nevertheless, I think this is such a good choice for a signature scent for the right person, yet 40 Knots is more of an "occasion" scent because of its demanding presence.