Quite a bit of rules changed due to player feedback. A GM advice chapter and a player advice chapter. Twenty-four additional full-fledged PCs, with the six from Prototype revised to the final chargen rules. Something like 30 total mission briefs/adventures. The real opening fiction, not a reprint of the SR5 opener (though the new piece is also by Rusty). Worth the $15 price of admission, I think.