Speaking text is the great mystery, though, for me. Like all of us, I certainly say things in a different grammar and cadence than I write them, and with voice recognition technology I can say anything I wish to write--and the version resulting is more different than what I would have typed or handwritten are different from each other.
when writing specs or final drafts I type
when writing poetry or journaling I write longhand
when writing dialogue or musings I use speech recognition
I'm sure there's fascinating psychology / neurology underpinning our various methods of communication.