PAIP is a good book, but personally, my mind was blown more by SICP and On Lisp. Both of those had more unique content and "lisp magic".
When I can find the time, I want to read Purely Functional Datastructures. Clojure and PFD are the first major advancement that I've seen since my college Intro to Datastructures class.
PAIP has some great code and explains more how to do version a), how to move to version b) and finally reach version c). The process is typical in Lisp: you do a quick first version and then refine it where needed by adding features or by optimizing it at the right places.
When I can find the time, I want to read Purely Functional Datastructures. Clojure and PFD are the first major advancement that I've seen since my college Intro to Datastructures class.