TL;DR: Kilian Paris (By Kilian) remains a premium niche house with a high price positioning, and opinions vary sharply by reference — some considered essential, others viewed as overrated by a portion of connoisseurs.
A house as identified by its packaging as by its juice
Kilian Paris has built a strong identity around refined bottles and luxurious presentation boxes, which plays fully into its high price positioning. An interesting point often mentioned by connoisseurs: the house offers a refill system, letting you rebuy just the juice without the decorative bottle — a way to meaningfully cut the cost for those who don't care about the collectible aspect of the flacons.
Rose Oud: the most commonly recommended reference
Across the whole catalog, Rose Oud regularly comes up as the house's most accomplished composition, combining good longevity with a composition considered more interesting than other, more commercial references in the line.
A judgment that varies a lot from one reference to another
Unlike houses with more consistent perceived quality, Kilian draws sharply contrasting opinions depending on the perfume: some enthusiasts consider the whole house overrated, while others admit to owning a few references they wouldn't want to see disappear from their collection.
Has the hype died down?
An interesting observation that comes up in more recent discussions: enthusiasm around the house seems weaker than a few years ago, without that necessarily calling into question the quality of certain specific references — more a fading trend than a judgment on substance.
How to approach Kilian without getting it wrong
Given the disparity in perceived quality from one reference to another, it's better to target specific recommendations (like Rose Oud) rather than approach the house as a whole — and take advantage of the refill system once you've identified a reference as a genuine favorite.