I had 375wpm and 82% comprehension. I was also watching (and paying attention) to a DVD of the first season of True Blood at the same time. And I had very little interest in the topic about which I read. I didn't retain very much of it as a result.
I am one who can read a book every day or two, depending on how much time I have (full time job, 3 kids in various activities, too much time on the internet.... all those things really cut down on my reading time!). I go through books like water sometimes...and then sometisem I take a break for a while and do logic puzzles or number puzzles instead