When I was a busy academic, I had to speed read. I learned the technique, and used it.
My comprehension improved. I took it all in, faster. I did argue with the author. How else do you approach research reports, journal articles and student essays?
The downside was that I found it difficult to read fiction slowly. What should have been an evening’s relaxation was over in half an hour. And yes, at the end of it, I could have written a detailed precis of the book.
This is not to set me up as some kind of a genius, but is I believe a fairly typical experience for speed readers.
Perhaps the author didn’t mean what I call speed reading, but just reading fast, without attention? That’s a very different beast.