Concurrently, given that more vault material from Hendrix has seen the light of day than artist-authorized, finished recordings, its also cause for scrutiny.
Now, I'm not a serious Hendrix bootleg collector, so I cant speak for the true rarity status of any of the material comprising Valleys of Neptune, the first release under the Hendrix estates new partnership with Sony's Legacy imprint. I can tell you, however, that if you've bought any of the compilations that Hendrix's official imprint, Experience Hendrix, has released over the past 13 years via MCA/Universal, you're already going to be familiar with different versions of up to eleven of the albums twelve tracks.