Just be careful not to get the DTS CD, which comes in a DVD-A sized jewel box and says DTS 5.1 MUSIC DISC across the top. The DTS CD mix was not used for the DVD-A and SACD, and many consider it inferior to the HiRez mix.
you mean don't get the DTS 5.1 mix for most any title, or for this ("Gaucho") title?
I usually prefer the SACD version if I have a choice, they seem to sound excellent and function more simply (no menu's etc.,...), unless they have a "live" concert DVD footage track.
No. There are many great DTS 5.1 CDs, including Alan Parsons "On Air" (an excellent disc, BTW). It's just that the Gaucho DTS CD came out first. It was a year or two later that it was remixed a second time for SACD & DVD-A, and the general consensus is that the second 5.1 mix is superior to the original 5.1 mix.
There was never a quadraphonic mix of Gaucho from the '70s. The DTS CD of Gaucho was one of the original 5.1 releases from DTS that was new and not a re-release of a '70s quad title.