I should stay away from corals but you know... I don't. And when one comes along with my name on it, literally literally, I'm all hook line and sinker. So I may be guilty of overidentification with this particular shade but there are worse things one can dote on; overpriced shoes, shitty HBO series, shady younger men. The list is endless.
I don't own many corals but MAC's recent Toying Around (LE) is quite close and possibly dupe-y, at least to the casual observer. Toying Around is a respectable Amplified shade and by far the most usable coral I'd encountered, but the poor thing just pales beside the Nars Audacious formula. Kelly is denser, slightly deeper, more intensively pigmented, longer-lasting and importantly offers a more flattering super low-sheen satin finish.
That's not to say Kelly is 4.2g of unmitigated perfection. Like most corals (and some other Audacious shades) she likes to skip the inside centre of my lower lip; not all the time, mysteriously, but often enough to be annoying and it can require a bit of pencil infill. She's not the first and won't be the last to pull this shitty move and you'll probably be fine if your mouth is paler than mine. Because of the brightness of the shade and her 85% opacity, she also exhibits a teeny bit of settling into lip lines, but there's more than enough endurance and malleability in the formula to remedy this without touching up for about four hours. That's great wear for something this vibrant and I don't really consider it a technical fail.
Try mixing your corals with eyefuckers like MAC Lady Danger and a bunch of other orange-reds and big warm pinks; you can end up with some amazingly idiosyncratic, jewel-like shades that are especially powerful on either really pale or really dark complexions.
I enjoy Nars Kelly quite a bit and do hereby testify that it's the least problematic coral I've personally encountered.
UD Catfight, Bite Zinfandel, MAC All Fired Up cool outdoor daylight