Not much difference. Even the spray components are likely very similar. The Malaysian ones I would keep on damp peat with a bit more moisture than you would give M. giganteus. They may be a bit more quick, but you can handle them easily enough.
Ive never had the Malaysian sp. I've had many Mastigoproctus giganteus that I caught in the wild. They are VERY defensive when first caught. They try to pinch and spray. But they calm down in a minute or less real fast after they've been handled. The ones I've had never acted real defensive after they've been handled. I've heard people talk about Mastigoproctus giganteus being "slower" than the Malaysian sp in captivity but I've seen Mastigoproctus giganteus act pretty crazy in the wild.