... to me it is a no contest, as their is only one "original" - and that is the Royal Oak, being the real pioneer of a new category of watches when introduced in 1972. And as the current model still has the Cal. 2121 inside, that history is well preserved.
Also, the design is more stringent with it's strict angular patterns - and with regard to the design principle, the real counter part to the RO is not the Nautilus, but the 1832 Ingenieur, following the round pattern. The article got it wrong in this respect, as the 1832 was not designed in the late 70ies, but in fact Genta started working on this directly after the initial success of the RO - so both Nautilus and 1832 were introduced in 1976 (the Inge actually a bit before the Nautilus), it was the VC 222 that followed later in 1977.
Perfect fit and you feel the difference to the 15300 - although it is just one millimeter:
And the price differential between RO and Nautilus could be wisely spent for this one:
Btw, the 1832 was the only one of the Genta Four with an inhouse movement (Cal. 8541ES, the Cal. 2120/2121 is based on the JLC 920 and was supplied by Jaeger)
So, would a swap these two for a Nautilus?
Not in this life ;-) ...
Cheers,
Christian