I bought this product purely on its description and reviews I read outside of BirchBox (because no one has reviewed it yet), and it is such a great product. I cannot attest to how much it has delayed the aging process (we will see in a few years!), but I can say it is a great moisturizer. It is very light, so if you have dry skin, you might need to use it with something else. It, seriously, feels like silk or velvet when you put it on your face. It feels so soft, and it doesn't take much product, either. I have noticed, over the past 4 days that I have used the product that my skin looks great. I have small wrinkles wanting to form on my forehead, and I am noticing them diminish already. The smell is great, too. It is so soft and subtle. The consistency is somewhere between an oil and a cream- more on the oil side, but I think that is why it goes on some smoothly. Anyway, I would give it 5 stars, but I haven't used it long enough to be convinced of its age delaying claims.
Also, as a side note, I am not crazy about the design on the bottle. There is a lot going on, and as someone who speaks French, there is never a dash over "u" and you never use hypehens, so I don't get that. Also, after one day in my cosmetics bag (I shower at the gym), the label has already started to come off in flakey pieces on my hand.