Could someone maybe post a FAQ clarifying the differences btw DVD-Audio vs. SACD vs DTS/DD5.1 CDs? I realize you need a DVD-Audio or SACD player to play those discs, but the ones coming out saying DTS/DD5.1 (DVD compatible) - does that mean I could play them in any DVD player? Is it essentially a DVD w/only an audio track? And maybe list the pros/cons of each type of media?