My motor control is so out of wack … I find that, for one thing, my accuracy depends on the keyboard to some extent: I'm slightly more accurate with Topre variable than Cherry brown/blue as the keys require more effort and offer more positioning feedback and/or forcing an extra fraction of time to react and process. I prefer the clean feel of mechanical, but Topre is definitely easier to type on. (At the moment, my work PC has my FILCO MX brown, Topre variable, and Tactile Pro 3 all connected.)
I don't really understand my own method of typing, but what I do notice is that my speed and accuracy vary wildly without obvious reason, from being able to bang out paragraph after paragraph at speed with few if any errors, to having to backspace blocks of letters repeatedly in pretty much every single word (more annoying if I keep backspacing a different number of keystrokes to how many I entered).
I am not sure whether it generates a greater or lesser cognitive load than touch typing – my fingers have to move more, so there's lower stress from ultra fine movement and awkward motions, but there's also a lot less reason and order to my finger motions. In general I have to get into a "zone" where my mental processing is correctly devoted to typing – typically when I'm writing a long and fully pre-meditated e-mail I can type rapidly and reliably, but if I have to think too hard or my focus is compromised (i.e. 98% of the time) I can't type straight to save my life.
I can't think engrossing thoughts while descending stairs, either, as my brain switches off balance processing and I just enter free fall and have to grab the hand rails. Every layer of my brain is weird.