Obviously we don't all like the same things. One commentator said it was all just talk, as if that were a bad thing. I happen to love language and words, and in particular love the French language. So that is the reason I rent a movie in French. I also have a very strong aversion to "action movies" where language is reduced to "Ow! Help! Duck!" On the other hand, movies like Gabrielle where minute movements of the psyche are explored in depth by minimalistic means, these are what grip me, move me, keep me interested. I do not really think the movie is like an opera -- it was more like a french play -- the delivery and velocity of the spoken word was very much in the style of french live theater.
My only caveat is that French-ness and Conrad seem a strange mix to me. There was another French movie that was made on a Conrad text, and I had a similar reaction. Conrad is not writing about French society. And yet the action has been transplanted to France. And it seems an entirely incongruous transplant to me -- plopping the joyless uprightness of puritanical England (the only place name mentioned is "West End Station" into a such a lively Latin culture which has always had a much more relaxed attitude towards love and sex... well,to me it's just incongruous.
Nevertheless, it was an cleverly crafted movie, and the musical score by Fabio Vacchi was unearthly beautiful.