Speaking from my own personal experience, my reading comprehension doesn't seem to suffer at all, and the speed at which I read seems to be much faster than average (for instance, if my wife and I are reading the same page of text, I'm done long before she is).
I have no strong concept of the sensory world of the text. I have a very, very vague impression of what a character looks like. I'm prone to forget explicit features that the author bothered describing because there's no durable image to factor them into.
I notice some people have strong reactions to casting calls in movie adaptations of novels. This objection is foreign to me; I had no strong image for it to conflict with.
I am more likely to find a turn of phrase beautiful for the words and sounds, than to have any sense that the thing it describes is beautiful.