The flexibility of having a computer read the text via text to speech is a huge benefit IMO. My reading speed is painfully slow but with espeak or a screen reader I can parse about 400 wpm.
One thing that helped me a lot was doing a keybinding for espeak via:
xsel | espeak -v en-us -s 400
I have a relative with dyslexia and it was a helpful hack for him to get reading faster too. Too bad this doesn't usually work as well in school settings where they use physical textbooks.