I will do a “changelog” free PDF with all the changes, but the new book was totally rewritten so it’s not an update. It’s the same rules, really, but we added a ton of new materials (20 classes, 2 more environment, 60+ new monsters, all the creatures and treasure from Fiendish Foes, new spells for illusionists and druids). I wanted to add more but we really ran out of space and couldn’t use smaller type.