I don’t feel like there’s a big quality difference… The most popular items have more people talking about quality, for instance: Van Cleef often has significant air gaps for Alhambra pieces, and Cartier commonly has loose screws in love bracelets.
For chain bracelets, Tiffany often uses thinner chains and daintier spring ring clasps. I’m not a fan of the delicate look, but I also don’t mind it that much. However, the hardwear bracelet is popular, has a distinctive look, and isn’t dainty. Diamonds by the yard versus Cartier legers, I like the Tiffany more, because the bracelet flips, and the back side of the DBTY looks better imo.
For bangles, I find that Tiffany’s newer pieces have much better designed closures compared to before. Nowadays, the closures are well-hidden and go seamlessly with the design. For instance, the Knot, T true, and Atlas X bangles all incorporate the closure into the design. I used to complain about the older bangles, because the closures weren’t very discreet.
For wire bracelets, like the Cartier juste un clou or Tiffany T, they all have that issue with being susceptible to warping. That’s just across all brands. I wouldn’t call that a quality issue, though, since the bracelets are hollow sheets of gold surrounding a thin wire. They don’t feel very robust, so it doesn’t surprise me if they get misshapen. They’re not meant to be worn 24/7.
For tennis bracelets, I think Tiffany is more famous with its Victoria collection than either Cartier or Van Cleef. Also, Victoria uses platinum instead of white gold, unlike the Cartier reflection, etincelle, or essentials collection.
Anyways, I guess whether or not I would go with Cartier, Van Cleef, or Tiffany for a bracelet comes down to design rather than quality. If you want a chain bracelet, I feel like Alhambra is more feminine, versus hardwear which is more unisex. If you want a bangle, the love is more iconic. If you want a diamond line bracelet, I think Victoria is more famous with the four marquise diamonds.
Either way, the jewelry from these brands is meant to last beyond a lifetime, and the stores will be able to repair and restore your pieces. I don’t think there’s a big quality discrepancy, if there’s any at all. A Cartier customer versus a Tiffany customer versus a Van Cleef customer are probably not using quality as the determining factor when choosing to buy their next piece. For me, matters of convenience, branding, inventory, uniqueness, and design take precedent, since I expect all jewelry from these brands to be of equivalent quality.