In my earlier years, speed reading was an in-thing to do. It was "viewed" as looking more efficient in completing your reading/homework. At that time, our class had reported their comprehension or lack there of, declining to 70-80%. These were studies carried out in 1982/83, in years 8, 9 and 10. By the time most had hit year 11, most had reported of reading at the preferred "normal" speed. Of course, our marks of final papers and exams had gone up also.
My comment is a fact of what did happen at schools in Melbourne, Victoria, Australia. It was also to see what students comprehension of the English language is (and was) as well as grammar in general.