Hold'em for Advanced Players Question

I read somewhere recently that HFAP dealt specifically with limit Hold'em and that it does not apply to the No Limit game which I play pretty much exclusively at this point. Is this true or would this book be well worth my investment even though I play NL. As a side note, what is the difference between Small Stakes Holdem and HFAP, I am currently playing smaller stakes, should I read both of them or is what's in one book pretty much the same as what's in the other...Thanks in advance