Any high quality source will sound better through a properly balanced higher quality Hi-Fi system, bearing in mind the caveat of subjective assessment. The specification of DSD requires greater bandwidth, frequency response, dynamic range and thereby a more linear phase response in the rest of the replay system, otherwise the full benefits of the SACD format cannot be realised. Sony has released a range of components which include these important design parameters. It is therefore simply not possible to give anything else than a generic statement to this particular question. If the SACD player, CD are SACD software have been engineered properly, then I believe that the SACD will always be superior.
Hybrid discs are a good way for subjective checking.
I have demonstrated SACD though very modest Hi-Fi systems and the improvement has been apparent. Eric doesn't answer the question but the question itself is vague. This layer is likely to be dropped as SACD players begin to dominate the market. It is entirely at the record companies discretion which type of the three variations of SACD discs they choose to release. Moreover, as the market grows it is again the record companies choice if they decide to release only single layer discs or not.