I tried this when reading Ready Player One (I counted to eight in my head to stop vocalizing). I did read it much faster (in fact, faster than my partner who is a native English speaker/reader). I cannot vouch for how much I remember of the book though. I think it's less, because I remember watching the movie thinking "oh, right, that's what happened" about a major plot part. That's never happened with other books that I first read, then watched the movie/series adaptation of.