I realized one thing lacking in this book for the feats: summary of the ability lines in the feat lists.
i.e. on page 160 where it lists all the general feats and skill feats, it doesn't say anything about what those feats do.
Looking at the 3.5 stuff for comparison; when it had the lists that summarized what all the feats were (i.e. name and prereq etc) it also had a short line telling roughly what the feat did.
in this playtest document; I can't tell anything about what a feat does except by looking up its full text.