Best version I have is one on a Return to Forever compilation album "Return to the Seventh Galaxy", which was taken from a local radio tape of the obscure second lineup of RTF that never released an album (Chick Corea/Stanley Clarke/Bill Connors/Steve Gadd). Bill Connors was absolute monster player in RTF, and I think I like his work in RTF a little better than Al DiMeola's, actually.
As to the question at issue, I'm probably not much help. My basic jazz philosophy is to keep to a couple of basic key centers and have fun with the chromatic passing tones. Not exactly a jazz purist!
I've noticed that the versions of "Spain" I've heard sort of 'go off' during the solo sections, and it might be that Chick never plays it quite the same way twice, even though the head of the tune is pretty ornate and 'fixed'.