The 2nd edition of Teaching from Rest contains 35% new content. I kept writing after the first edition e-book was published, and that writing went into second edition! Also, Dr. Perrin put me through my paces with edits and helped me get the book juuuuust right, so things have been reorganized and revised somewhat.
The Audio Companion has not changed at all. The printable Companion Journal has been reorganized to match the order of the 2nd edition book, and contains maybe 10% new content. If you have the Companion set from the 1st edition, you probably don't need the revised set.