Now HIP has made its way into the Classical and Romantic eras - in short, the standard orchestral repertoire. For many reasons, I believe they'll remain largely an addendum here. Second, I can't imagine these organizations giving up their bread and butter. When we think of the Next Great Conductor, we look at interpretations of a few pieces, mainly Austro-German, and think of large modern orchestras. The field seems more open to just the kind of rethinking HIP represents.
Nothing justifies a theory like an actual great performance.
Brahms's string sextets represent some of his most gracious and beautiful chamber writing. For these works, I grew up listening to a lush modern sound I could wallow in, and in large part that sound became part of my conception of the piece. L'Archibudelli upset my expectations and consequently shocked me. I must say that the playing itself is marvelous, the chamber ideal of each player simultaneously shaping his own phrases independently of the others and subordinating his matter to momentarily more important lines. However, with these gains, we lose the rich sonorities of, say, Heifetz and his friends.