My 6 year old DS has developmental coordination disorder and probably also motor dysgraphia (I just posted on the thread about it). Digit span and coding were his two lowest scores (both 10's). He also seems to be a visual-spatial learner in that he hit the ceiling on some of the subtests of the visual perception test he took (for instance visual memory and visual-spatial ability). When he was 5, he memorized a map of the U.S. that I put on his wall as a decoration, and this was right after a traumatic brain injury from which he had brain damage and one eye was paralyzed and stuck in place in the corner by his nose. So he had double vision at all times unless we patched his other eye (we always had to patch the normal eye). So he had major issues with his vision.
What seems odd is that he is so visual spatial you'd think he would be poor at phonics and decoding, but he can decode just about anything using phonics, even words he's never seen before (he reads them kind of like a computer voice). I don't think there are clear links between how visual-spatial a kid is and how they learn to read, at least not for everyone. And even on the perceptual vision test that he did he was using auditory strageies to remember the information. For instance on one of the tests there would be a series of numbers or letters and he would have to pick the right one out from a multiple choice test on the next page. When he was looking at them, he read them aloud and remembered the images based on auditory strategies and also looking for patterns in the sequences. On another test where he had to recall a picture, he was also looking for patterns and saying them aloud, for instance "This picture has the planet Uranus inside of a cabinet." (he talked to himself through the entire test which was fascinating--we could see how he was figuring everything out). When he recalls where the states are based on memorizing the map in his room, I'm not sure if he is forming an image in his head or not, but he knows what shape they are and how they fit together--like puzzle pieces. He is able to draw them from memory and when I ask him how he knows things like Nevada being next to California he says it's because they fit together (in a "Duh, Mom" type of voice). Do people who are "visual spatial learners" really think in images, like a photographic memory? I don't know--I think they may just be seeing patterns in everything or how parts fit together into a whole.
Just some observations I've made in terms of my DS--not sure if it helps or not.