Speed Reading is for dime novels. If i read a book and i can understand everything easily when its not a novel, im not reading it, there is nothing to learn from it.
You can read Platos republic and think really hard about every sentence. If you speed read it im pretty sure u learned nothing.
depends how you understand speed reading. There is the breezing through the book at the speed of light... kinda skimming it as it were... and then there's the actual process of reading without the pronouncing all the words in your head as i described above.
that's an actual problem some of us have, that other don't have, and usually you have a hard time even explaining it to them, because reading in a way that they do (i believe the correct way) is so natural and engrained, they can't even imagine any other way.
but yes, I agree hard texts take a longer time to read because you're moving from sentence to sentence, parsing them, pondering, ... but this would still be done faster by a normal reader, than it's done by me and people like me.
I've finished Kane and Abel in 24 hours and The Fountain Head in just 2 days. I've read total 78 Books in 13 month of my incarceration period.
Maybe its start with how you think, not everybody is thinking in talking to himself. But i don't think that anyone will be breezing trough a completely book with an unfamiliar topic and can takeaway anything from it.