The cd's been remastered a fair few times, a new one seems to come out every couple of years. I myself have 3 copies, one from the early nineties, a second which, given its 'millennium edition' tag, must date from somewhere around 2000 and the third is as part of the miles davis and john coltrane box set (which I think dates from also dates from somewhere around 2000). Each one seems to sound progressively better (in the order listed). Having said that, I wouldn't necessarily buy it for the alternate flamenco sketches, like most alternate takes it wasn't used because the other one was better.
That said, the mastering on the box set, is outstandingly good, so if your cd is much older than that, it might be worth splashing out on the new one.
I also have it on vinyl, and that tops all of the cds

Also worth noting, the album sounds brilliant in any mastering I've ever heard.
regards,
Tam