The Archetype/multiclassing system has promise: I was excited by the lifepath system before they released the playtest, but found it lacking at the time: it will be interesting to see if that is improved in style.
I don't expect to convert my games from 5E, Savage Worlds, Call of Cthulhu, and Dungeon World (am I really running THAT many games? haha). That said, I will probably pick up the book at some later point. I like Paizo's art direction and I might be able to glean some useful ideas to port over. In particular, I might use some of it to prop up 5E to expand its tactical combat options.