I've set about answering my own questions by visiting the Gramophone's archive of reviews.
It seems that Bernstein goes for duets and Abbado doesn't.
This 1989 review by Richard Osborne http://www.gramophone.net/Issue/Page...7.#header-logo carefully considers the Bernstein/Concertgebouw, Chailly and Tennstedt recordings against the reference of DFD/ES/Szell and declares the latter to be still the champion, literally on points (he resorts to awarding marks out of ten for each song).
Interestingly, he says (end of 1st page) that Mahler 'certainly envisaged' duet performances. So now I'm even more confused!
It seems that Bernstein goes for duets and Abbado doesn't.
This 1989 review by Richard Osborne http://www.gramophone.net/Issue/Page...7.#header-logo carefully considers the Bernstein/Concertgebouw, Chailly and Tennstedt recordings against the reference of DFD/ES/Szell and declares the latter to be still the champion, literally on points (he resorts to awarding marks out of ten for each song).
Interestingly, he says (end of 1st page) that Mahler 'certainly envisaged' duet performances. So now I'm even more confused!
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