Palmer came along a couple decades late for me, but I've read it. Papazian was the first seemingly comprehensive and authoritative book I found.* Neither has had a place on my shelf for a long time. Same goes for lots of other books. If my reference shelf is now filled with more technical, professional oriented works and historical texts, that doesn't mean all the other books weren't worthwhile (though some are now outmoded.) Everything I've read has played some part in my education. Read all you can. Eventually, as you evolve your own priorities and refine your critical faculties (gaining your own expertise,) you will recognize some sources as more useful than others; but you only learn to evaluate information through continued exposure to as much information as possible. Same as in any field. Don't stop at either Palmer or Papazian.
(So short answer, both.)
*EDIT Seemingly. As I recall Miller and Noonan were the first to really fit this description. Miller really got me going, and Noonan is the only one of the old books I might still occasionally look at.