As the happy owner of a different limited edition Arabic numeral Santos-Dumont and as a retired design professional, I admire Cartier's longstanding excellence (even supremacy?) when it comes to watch design, and the Santos models in all their forms exemplify the company's rich heritage in this regard. The Santos de Cartier and Santos-Dumont remain distinctive, compelling, and instantly recognizable after over a century of development.
Without in any way disparaging Cartier, though, I would draw a distinction between design and horological content. No question that the Santos variants, the Tank, the Crash, and the Tortue, among others, represent pinnacles in watch design. Barring some of the Collection Privée releases, however, Cartier's mechanical (horological) components don't often match their designs in quality and finish. The Santos-Dumont is a fine example. While the case, dial, enamel work, and dial fittings as described by King of the Road are peerless, the Santos-Dumont runs on a perfectly capable, but undistinguished, Piaget-sourced manual wind movement, which does not match contemporary standards with its very short power reserve.
Don't get me wrong, it is a great watch, but it has square cased peers - say, the Bulgari Octo Finissimo Automatic, for one - that marry distinctive and effective design with far greater horological interest. I do applaud Cartier for sticking to nicely engraved solid
casebacks in its Santos collections. They represent a strong argument
that a transparent caseback is not always a positive design feature. I must also point out that there are plenty of competing brands that offer compelling mechanical features and finishing, but whose deigns are relatively undistinguished, or even clumsy. Cartier, as a brand, seems to know what it does well, and leverages its design chops effectively (as long as Richemont lets it).
The Santos-Dumont XL, Ref. #WSA0025, circa 2021.
I didn't buy a Santos-Dumont for it's horological content. I bought it because it offers a magnificent design that enjoy wearing, and I don't believe that Cartier really needs to do more with the movement in order to keep the line successful. Cartier's current standing in the watch sales hierarchy speaks well to this.
Best to all!