i also can't read w/o the little voice in my head, but it is an interesting idea.
is there a website to test reading speed + comprehension? i'm thinking something w/ like an auto-generated story of fixed elements ("a pig and a horse visit the blue house on the hill", "a donkey and an ostrich cross the bridge over a river"), or maybe just a sampling of a large corpus of real text of similar level. you get timed on how long it takes you to read it + given a basic test to see if you actually absorbed it.
would be interesting to get some numbers, and also see if these (mythical?) non-subvocalizers really are faster.
i think i could see it maybe working, but i also feel like the words would be taking a whole new path through my brain. almost like a new language.