Disc one for Subsistance is Snake Eater with a full 360 camera. Instead of the camera type angles from the original Resident Evil's, you can now pan, rotate and zoom in. It is very helpful.
Disc two, Persistance has the Secret Theatre, which is basically bloopers. The new duel mode, which allows you to battle the bosses again in attempt to score the most points. There is more extra stuff, but the main reason for the disc (online play) is no longer available. --- Metal Gear Solid Fanatic