I have used just the PR step on old text books. Unfortunately I really don't get much call for using that information.
Once I PR'ed a fiction book which I had read about 10 years prior and had a purpose of recalling details that had faded away. It was kind cool. I started remembering details while I was PRing. This is an experience I've been meaning to revisit.
I would say do it. You're mind is very powerful. PRing is a great way to get by the conscious filter, which is very important for comprehension.
To the point of comprehension. I remembering reading one page in my fourth year quantum text. As a reference quantum physics was one of my favourite courses. Anyways, after reading the page 5 times and still not understanding what it was trying to say, I read it one more time. This time I just read it as fast as I could, not bothering with all the details logic on the page. The neat thing was that there were about 5 items presented on the page. You needed to be aware of all 5 to follow the logic at the bottom of the page. Going through the book at regular "textbook" speed I would forget all but the last two issues by the time I got to the bottom.
Extending this, I've notice that some courses only make sense during the final review. This is because your mind has to have all the ideas present and revelent at the same time to draw the connections. Now isn't PRWMS a great way of putting it all in there in short order so they can be considered as a whole.
Adding to this, I've always found that details are easier to remember when you have a fully understood skeleton (model) on which to hang them.
You are perfection.
Iam2 
