Update: Sept. 3
As a result of a twitter conversation, discovered this blog post by Timo where he says most loud endings of modern compositions are ineffective. Most of his pieces end quietly (notable exception, "Flirtation Avenue" in "Shy and Mighty" and the "Home Stretch" concerto (as I remember). But then there is even a theory that Bruckner would have ended the "ultimate finale" of his Ninth Symphony quietly, following the example of the first movement of the Eighth, link here. For the Eighth (Oct. 25, 2014), one could argue that the quiet first movement ending simply allows the Wagnerian triumph at the end of the "Apocalyptic" Finale to seem more conclusive (true of my own Sonata 3). Actually, the same dilemma is true with Tchaikovsky's "Swan Lake", where a recent Bolshoi performance picks the soft ending, where as a UNC orchestra performance makes such a case for empty triumph instead (as in the movie "Black Swan").
See post July 29 for posting about the way (soloist) performance depends on the piano itself.