I've said this before, but I figure it's appropriate to restate.
PRing is a tool like any other tool. It helps you read more efficiently. How you use it depends on your habits.
Unfortunately, a large portion of people enticed by PRing are procrastinators (I know I am.) Procrastinators, of course, are going to be turned on to the idea of a program that lets them rip through books, because we all remember a time where we had to study or read something at the last minute.
The habit of procrastination in the realm of photoreading would go something like this: If you procrastinated before PRing, you probably studied the night before a final. If you procrastinate after PRing, you'll study hours before; in fact, because PRing works better when you're relaxed, the stress of "the final hour" will most likely screw you up big time.
I procrastinate as bad as the next guy, because I have bad study habits (at least when it comes to school).
I would recommend using the "Get to It" paralminal, although as sad as this is, I've bought it, tried it, it worked, and then I've procrastinated on using it again.
That's right, I'm procrastinating on my procrastination paraliminal tape.
It did help when I used it, though, last year; I retook one class I failed in the year before and got an A last semester in the same class.
Anyway, I guess my point is that if you procrastinate, PRing isn't the solution, it's still just a tool. How you use it depends on your study habits.
-Ramon
PS - I hope that doesn't sound preachy; like I said, I'm a horrible procrastinator myself. I'm not critiquing anybody, just figured I'd mention it again because the thread seemed appropriate.