DD and I are both highly V/S people, and both of us are really excellent (and natural) spellers, as well. Completely morphological and grapheme-based, in my case. I can't spell very well using auditory/oral pathways at all-- when I did spelling bees, I used to "write" the word by tracing my index finger on the palm on my hand-- because I "see" the word and know if it is correct based on visual information.

It's not systems based at all.

Schrödinger's cat walks into a bar. And doesn't.