Ok, the main disc of the individual release is exactly the same as in the box set. All the new material is on disc 2, which is as follows:
BTTF:The Ride - all the ride footage from the Lobby and the Ride itself
Looking Back at the Future - new retrospective documentary
BTTF Night - Hosted by Leslie Nielsen. Bits that were in commercial breaks during the first NBC airing of BTTF
Q&A with Michael J. Fox