It is true that there are more textual interpretations of Tchaikovsky's 6th than this: Mravinsky, Fricsay, Cantelli, Toscanini, Reiner, Monteux, Dorati... And more coherent versions scaled and structured with outbursts (Mravinsky, Svetlanov) or more "romanticized" readings (Mengelberg, Furtwängler).
It is also true that the tempi Bernstein chooses for this version are larger: he takes 5 minutes more than Cantelli and Toscanini just in the first mouvement.
But if you are interested in a version that is also an interpretation, a reading deeply rooted in the nature of this symphony, "pathos" (suffering), as a farewell to life and music, it is all here. And, after some time, Bernstein will show how coeherent he is in the overall approach of the music: the two central mouvements sound "fake", with a plastic joyfullness - exactly like Mahler's 9th. After hearing this version, I could finally understand Mahler's 9th, Mozart's Requiem, Bruckner's 9th, Brahms 4th. It is the end of music for a composer, a requiem that embraces all life and music in the same expectation.
This is an experience. An excessive one. If you want to enter deeper in the essence of music, this kind of alchemy will poison your soul.
It will never be "your only" version of Tchaikovsky 6th. For a more balanced version, try Fricsay, Cantelli, Mravinsky, Toscanini. For a musical excess, for a rebirth through death, drink this, as if it was Tristan's drink.