I just bought the Wergo Earle Brown set that includes Ives' Concord Sonata played by Aloys Kontarsky. In LP days, when I was poor, I had the Kilpatrick, which unaccountably (and unforgivably) does not include the flute or viola parts, and was quite happy with it. I got the Kalish much later, for the flute and viola, and wasn't much taken with the whole venture. Then I stopped buying versions of the Concord.
Until yesterday. And the Kontarsky, which I had known about but never heard, is fabulous. And the flute and viola parts are played as if they really belonged.
Plus, since this is a three disc set, you also get that outrageous Sonic Arts Union disc of Ashley, Mumma, Lucier, and Behrman and a disc of music for flute and piano by Evangelisti, Berio, Matsudaira, Castiglioni, Messiaen, and Maderna.