I'll be the first to admit that I don't know jack about Cuba Paris. I'm aware they exist, and I've read reviews that praise their scents, so when a fragrance salesman dropped a free bottle of Cuba Grey into my bag with a recent purchase, I was immediately interested in it. I'm not predisposed to liking Cuba Paris frags, because I find their packaging gimmick abysmal. The whole glass cigar shtick is ugly and unnecessary - Cuba is known for other things. Czech & Speake has a subtler approach that still pays homage to the culture. Still, it's wrong to write off a company just because you don't like their packaging aesthetic. So I'm glad I crossed paths with Cuba Grey.
I recently did a sniff test with my parents (who never read this blog) and asked them to compare Cuba Grey with Eternity for Men by Calvin Klein. I obviously had one of the pair on each hand. They both immediately acknowledged that these scents are similar, but not the same, and my mother felt Cuba was lighter, airier. My father had a more difficult time discerning a specific difference, but just felt they were different. It took him two tries to make that call. Both corroborated my findings: Grey is different, but very similar to Eternity for Men, to the point where it's a bit tough to tell the two apart.
The main difference is in ingredient quality and dosage. Eternity has been reformulated into a bit of a chemical blob (it always was one imo), and its current incarnation yields a deceptively fresh lavender note, chased by a gummy mandarin/lavender/sandalwood accord, a typical bottom-heavy late-eighties fresh fougère in the tradition of Cool Water, Drakkar Noir, and Skin Bracer, but without their transparency. It's heavy, forceful, and it travels across a room faster than a convict attacking his lawyer. In some cases, depending on who wears it, you'd rather deal with the convict than Eternity.
Cuba Grey is almost the exact same fragrance, a shameless Eternity clone, but it's lighter, its fruits more Calone-like, with a nineties fresh-sweet breeziness found in typical masculines of the day. Beyond that, I can't smell any significant difference. My parents couldn't either. Of the two, Grey has the edge, for the arguable reason that its aroma chemicals lend its construct a negligibly more natural affectation than Eternity's foghorn. Both are entirely synthetic, but they seem to diverge in the type of atmosphere their synthetics generate for the wearer. The all-business approach is Eternity, while the havin'-fun-in-the-sun spiel applies more to Grey. Its lither dosage of faux citrus and sandalwood means the freshness of old-school gummy lavender smells fun, not forced. Still, this could be splitting hairs.
Try Grey if you like Eternity, but can't bear its heaviness. Just know that if you apply Eternity and gently wash the spot where you sprayed it, you'll wind up with a 99.9% likeness with Cuba Grey. Kind of makes you wonder if you should eschew both frags, and just wear something like Horizon or Cool Water instead.