Villan, I think it's the range of typefaces and sizes against a dark background. The accessibility people at the places I teach tell me that those who suffer from dyslexia can "skip" information that is in a different typeface, but I am not dyslexic so have no personal view.

Also there seems to be a lot of information behind tab buttons - how well does that work with braille readers?

Will's, the one he did for Ian Fyvie, gives waht is needed in an instant. Faldingworth one needs to work at.