Based on reactions from co-workers though, it seems I'm much more efficient at touch-typing than most of them, even on a fullsize keyboard. And the experience does translate to a physical phone keyboard, even at the smaller size, so that may well be where some of the disconnect is.
Note also when touch-typing on my phone, I get the full speed by using both thumbs, not just one.
Case in point: people spelling "definitely" as (I assume) "definately" only to be autocorrected to "defiantly" without noticing. That sort of "correction" completely changes the meaning of a sentence.
Every time haptic feedback turns off for "power saving" when I'm running low on battery, I immediately wonder how anyone ever manages to type anything at all without mucking things up all the time.
I'd still prefer a physical keyboard, though.