I don't have experience with the Sony SACD SA777ES, and as much as I'd hate to recommend anything Sony, it would have to be much better than the Denon. I demoed the Denon a long time ago before I became a dealer and had no idea why it was popular. Sure, it was built well, but the sound quality was certainly lacking. After me, someone else I know did a reality check demoing the same piece in his system and came to the same conclusion as well.