The professor may be quite right in his assertion of the speed limitations on the eye. However, this argument treats the photoreading step as if it is speed reading. It isn't. The professor appeared not to know what the PR process was. I can understand why you would base decisions on an article written by a journalist, based on an advertisement. That is much more credible than the experiences of people who are actually using the system.
For an interesting discussion of the capabilities of the subconscious (or unconscious) mind, try reading "The User Illusion" or "Hare Brain, Tortoise Mind". Neither book addresses PhotoReading, but both present a compelling case that the capabilities of the unconscious are far more vast than we realize. If you believe that your brain's abilities are restricted to the small sliver of conscious awareness that you have, so be it. It seems evident that the brain actually absorbs and processes far more information than you can ever consciously comprehend. Ever ducked a ball that you saw out of the corner of your eye? If you had to rely on your conscious mind to dodge the ball, you'd eat the ball. Ever lost a set of keys (or other object) and then later saw an image of where they were? Your brain may have filtered that information at the time because it didn't seem important, but the information went in and was later retrieved.
The argument boils down to whether or not you believe the unconscious mind is capable of taking snapshots of a page of text and then using "optical character recognition" to gather and sort the information. My crappy little PC can do it. I don't think it's a stretch to think that your brain can do it. Your brain obviously has OCR type abilities or you wouldn't be reading this. It isn't paranormal. It isn't spirit guides. There are no crystals required.