My experience with an elite based amplifier(ICE based SC35, very different from yours) and heritage line is that the SACD format and the 5.1 music recordings are about the best you can get in a disc format that is non analog. SACD is a tad better than a greatly mastered CD presentation(I find that many CD's playback is nearly unlistenable)and a 5. disc is far superior to a sacd as far as my limited collection of both those formats goes. the surround sound function does seem to add quite a bit of soundstage, but it's still mastering dependent as to how good it is during playback.
the two sacd players I have had for comparrison are only the PS3 and the Oppo 93.