The argument against 3x seems to be a false dichotomy. I'd like to see a comparison of the author's recommendation of spaced repetition combined with "Mike's"

The argument against 3x seems to be a false dichotomy. I'd like to see a comparison of the author's recommendation of spaced repetition combined with "Mike's" 3x speed-listening. Increase your intake density and still get the superpowers of retention that SR proffers. Per the author's charts you can increase the information density by either switching languages or speeding up the current language, so find the maxima of the information density-vs-syllabic-speed graph and make your chosen language match either / both parameters. That may not end up at 3x, but human perception and understanding is certainly greater than 2x common speed for English speech. I don't have a citable reference at hand, but a motivational speaker from my youth made this point. He said he speaks at about double the standard rate because nearly everyone can still understand him, and it lets him give twice as much detail in a story, or tell a story twice as long as he otherwise could.