Thank you so much for your prompt and thorough response, Ralph. And I must say I've much enjoyed your forays into this area, precisely because they come from a different perspective. I recall that a recent compilation Rameau disc was reviewed on MWI by both yourself and Johan van Veen, and to my delight I found that both reviews gave a very precise and informative sense of the character of the recording, even though their conclusions were very different. To have either one of those reviews on its own would have been quite adequate; to have both was a rare luxury!

In this case, I wasn't so much wishing to learn the characteristics of the earlier recordings (since I already own them) as to find out how the new one compares with them. I fully agree that both of them are unevenly cast, but I wonder how far the new one differs in that respect. Of course one needs a very different level of tolerance in Rameau than in 19th century opera!

I'm also a bit wary because, in Vashegyi's earlier recordings, I've tended to find his conducting a bit too wooden for my tastes--perhaps because he "aims to represent the ultimate in authentic period practice," something that neither Harnoncourt nor Christie attempted (indeed, H repeatedly scoffed at the idea that such a thing was either possible or desirable). There could have been no modern-style conductors in Rameau's day.

The Naxos recording isn't of the 1737 Castor but of the substantially different 1754 score. For my own private use, I've made a very rough mud map to distinguish the recordings of the different versions of the Rameau operas, and perhaps some other people might also find it helpful. The list contains only commercially released audio recordings, and only of the operas that exist in multiple substantially different forms:

HIPPOLYTE ET ARICIE
(mixed) cond. Lewis (Oiseau-Lyre, 1966)
(mixed) cond. Malgorie (CBS, 1978)
1733 (with modifications) cond. Minkowski (Archiv, 1994)
1733 cond. Christie (Erato, 1996)
1757 - ?

LES INDES GALANTES
(mixed) cond. Malgoire (CBS, 1973)
1735 cond. Paillard (Erato, 1974)
1735 cond. Christie (Harmonia Mundi, 1991)
1761 cond. Vashegyi (Glossa, 2018)
1761 cond. Tournet (Versailles, 2019)

CASTOR ET POLLUX
1737 cond. Harnoncourt (Teldec, 1972)
1737 cond. Christie (Harmonia Mundi, 1992)
1754 cond. Farncombe (Erato, 1982)
1754 (chamber version) cond. Frisch (Auvidis, 1997)
1754 (chamber version) cond. Mallon (Naxos, 2003)

DARDANUS
(mixed) cond. Leppard (Erato, 1980)
1739 (with modifications) cond. Minkowski (Archiv, 1998)
1744 cond. Pichon (Alpha, 2012)
1744 (different version) cond. Vashegyi (Glossa, 2020)

ZOROASTRE
1749 cond. Kossenko (Alpha, 2022)
1756 cond. Kuijken (Deutsche Harmonia Mundi, 1983)
1756 cond. Christie (Erato, 2001)

It's surprising that the list contains no complete recording of the 1757 Hippolyte. Surely I must be wrong about that.