As the title says, my fundamental question is: How well do the older books for Mage the Awakening 1e work with 2e?
This question: Which Mage: The Awakening sourcebooks are essential? is obviously related and Which Mage: The Awakening sourcebook (if any) has info on mages' daily, non-adventuring lives? is tangentially related.
This almost comes down to "How much has changed between the two versions?". If there are fundamental differences, then the older books will be of no help and I'll have to wait for updated versions. If the changes are minor, then likely all of them will play well. It could also be that some material that was formerly supplemental has now been incorporated into the core making a prior book less appealing.
I am particularly looking at "The Tome of Mysteries", but that book also looks like the one most likely to have been superseded either by rules changes or having its best material built into the new core book.
Thank you.
Best Answer
As of this writing, the only mage-the-awakening-2e book that's available is the core book, so my answer draws mainly on that. The system by which spells are cast has been revised to a great degree — Reach, yantras, paradox pools…all these differ from the spellcasting system in mage-the-awakening to a greater or lesser degree, so you'll probably get less value from those parts of printed books. Moreover, many mechanical elements of the Order books are superseded or included in the 2E core, so they'll be of less use to you.
On the other hand, books of lore (Astral Realms, the tarot book) will still be good for you, and even the old books will have examples of rotes and legacies that, under the new mechanics, will be even easier and better to use.
David Brookshaw, the developer of Awakening 2nd Edition, recommends the following 1E books for a prospective 2e player: "Astral Realms, Secrets of the Ruined Temple, Left Hand Path, the six Order books, Intruders, and Summoners"