Noise shaping is a great method of improving sound quality, and can only be used with DSD. So if the same amount of data was used, and the componants were of equal quality, DSD would probably win...
But SACD uses a sampling rate of 2.8 mhz, which is much closer to the low end of DVD-A (96khz x 24bits) than the high end (192 x 24) (2.8mhz@1bit / 24 bits = 116khz). Considering how much less data it uses, i seriously doubt it can compete with 192khz DVD-A
And i think the sound quality of DVD-A currently avalable isn't any indication of what the format is capable of. To my knowlege, all 192khz DACs currently available are the delta-sigma type, which means the dac is basically converting the PCM to DSD. Of course this process is not as good as SACD which is kept in DSD the whole time.
But once they start producing 24bit R2R-type DACs for DVD-A, i think they will beat SACD. Of course, those chips will be super expensive, but keep in mind that the best DAC chips currently on the market are still less than $50. Why audiophile equipment manufactures are able charge 50 grand for the DACs, and why people buy them is beyond me...