Good for one already acquainted with Portuguese
Prista, the author, recommends coming back to his book from time to time as one becomes more familiar with Portuguese. I found this to be very good advice. I looked at Prista's book when I was new to Portuguese, and didn't have many real-life examples to relate it to. But now that I have some familiarity with Portuguese from reading and hearing it, his grammar book makes a lot more sense to me. I find that in my reading, I am able to scrutinize inflections and thus extract more meaning from words, thanks to the preparation I got from Prista's book.