I am really loving the packaging of this lipstick. It comes in a gold mirrored case, with the YSL symbol engraved in red. I think the mirrored casing is a really smart idea, since you can apply the lipstick without having to pull out an extra mirror, and I wish more lipsticks were packaged this way. I do like the formula, the #6 is more slippery than #20 which I find to be more creamy and pigmented. #6 is a really great nude, its a bit more pink than it comes out on camera, and I think it's a perfect color for a smokey eye, while still great on its own. I am also really loving #20, which is a beautiful cranberry red with a slight satiny sheen to it. It's an elegant red and highly pigmented. I tried #1 Le Rouge as well, which is a classic red, but it just didn't look good on my NC20 complexion. I think Le Rouge would look great on someone fair and more cool toned.
#6 has medium coverage, slightly on the sheer side. Since my lips are very pigmented, I feel that I need to apply more coats to get the look that I want. The only thing that I have against the nude lipstick is that it accentuates any dry patches on your lips, so it's probably best worn after exfoliating.
I definitely recommend this lipstick, great formula, colors, and packaging. I received a sample from the YSL counter, containing three other colors, including #1, #9, and #10. I will do a mini post on these with swatches soon. Stay tuned!