My complaint would be Andrew, well naturally enough I guess focuses too much on his personal experience when describing what works for INTP's. For example writing/blogging, he talks about that as an avenue for INTP's a lot. The problem is Andrew doesn't have a wide variety of life experience here, he's been fairly narrowly focused. To be fair he used to be really biased, but has since broadened his view to admit that (gasp) INTP's might like computers, for example.
He also pushes the meditation/breating agenda. I've been doing both for long than he's been alive, and yeah OK they help, but there are much better things an INTP can do. Anyhow, you can't blame a writer for writing from their experience, but do note this when reading the books. Despite that though he does do a good job of trying to generalize it, and yeah he got out and wrote these books, not me.