Supposedly, the biggest advantage to 24/96 or 24/192 for that matter is the 24-bit data word, which allows a much lower noise floor, far more headroom during recording, and finer-grained loudness level tracking. To be honest I've never a difference between CDs and SACDs on my system, and I'm not sure the difference is audible. I have no doubt that for recording the extra headroom is a big advantage, but for playback I'm not convinced.
The higher sampling rates enable the use of less intrusive digital filtering circuits (better time-domain accuracy), which could make playback more accurate in the 20-20KHz bandpass, and maybe I just haven't heard the right equipment yet. Dinosaur that I am, I still haven't heard anything, from any source type or signal, that sounds better than my Levinson No39 CD player.
