Certainly the best version of the Second Orchestral Set that I've ever heard.
From my Charles Ives site:
This recording is another demonstration why, in my view, Tilson Thomas is the most consistently fine conductor of Ives' music. He has the clearest command of Ives' musical idiom, and he makes this work come alive. The first movement is both familiar and mysterious, characteristics that MTT regularly discovers in Ives' music. The second movement has a swinging, rhythmic flair lacking in any other recording. The third movement is as epic and audacious as anything Ives ever wrote. Tilson Thomas captures the spirit of the movement. It's both tenderly elegiac and resolutely determined. Ives considered this to be one of his greatest musical achievements, and it's easy to understand why: It sounds great! My recommendation is that you play this exultant music very loud! The Concertgebouw Orchestra plays with an unparalleled, refined power. No surprise there. But perhaps a bit more surprising, they play completely idiomatically. They sound very much at home in Ives' unique, very American sound world. This is one of Ives' greatest works, wonderfully played and recorded.