Want to say I'm about halfway through the Dyslexic Advantage book, and they've done an excellent job of making use and integrating research I've been following for years. I think the 2E/dyslexic scenario is far more common but frequently missed or misidentified.

I'd recommend the book to anyone dealing with the extreme of visual spatial abilities. Most of the visual spatial materials I've read miss many of the secondary implications that the Eides have managed to tease out through research, anecdotes, and their practice.