When you skip the photoreading step are you satisfied with your comprehension of the book? Have you activated a book without sleeping on it... You know you dont have to wait overnight to get the benefit of photoreading the book.
In anycase you need to do what works for you. If you're happy with skimming and speed reading a book in thiry minutes great. I only would like to point out that this information is only in the short term memory. More work is required by the individual to place it into the long term memory. Most likely you find that the information you skimmed through you won't stay in your long term memory. For some things it isn't about speed it boils down to quality and purpose. If I want information out of a book that I can use immediately I can photoread the book in about 3 minutes. Why would I want to spend 30 minutes skimming?
Alex