Hi, John!
Of course Garbo is superb here; I think it is the definitive performance of this iconic role; Barrymore and Henry Danielle are also excellent. Had MGM provided Garbo with a more subtantial Armand (sorry, but I have never acquired a taste for the shallow Robert Taylor), "Camille" might have been very close to a masterpiece.
Respectfully, I take issue with your assertion that Garbo's loss of the 1937 Oscar for Best Actress was one of the Academy's 'greatest travesties.' Garbo lost to Luise Rainer for "The Good Earth" and, in my opinion, Rainer -- who is absolutely unrecognizable and never less than convincing as the Chinese peasant wife -- easily deserved the award. Looking at archive footage of this remarkable actress, as well as the recent interview with the 101-year-old Rainer that Robert Osborne did a couple years back, it is clear to me that Luise Rainer had an ability to completely disappear into the most complex roles that is pretty much unparalleled among actresses then at work in 1930s Hollywood. Rainer does an equally remarkable transformation when she becomes Anna Held in 1936's "The Great Ziegfeld," for which, of course, she also received a Best Actress Oscar. I suspect Rainer is not given her due now, because she is less known to us as Garbo, and since we have little sense of what the 'real' Rainer was like as a personality, it is difficult for us to gauge the effectiveness of her transformations into the characters that appear in "Ziegeld" and "The Good Earth." I wonder how many people assume that Rainer was pretty much like Anna Held in real life!
None of this is really meant to take away from your eloquent tribute to Garbo, for whom I have great admiration. On the whole, though, I do think I prefer Garbo's work in films like "Queen Christina" and "Grand Hotel" (the latter being, I think, a vastly underrated performance). Of course, Garbo didn't get nominated for either of those films, so go figure! I guess people have always groused about those biazarro Oscar nominations. Viva Hollywood, I suppose.