Using the typing test on this site, I (theoretically) type about 70 wpm on a keyboard and 25 on my Digid layout on the Twiddler. Using the more realistic 500-phrase set from I.S.MacKenzie & R.W.Soukoreff 2003, I only type 55 wpm, so let's say I might be at about 18-20 wpm with Digid. I think I have settled on a full Twiddler configuration that includes ten accented Portugese/French letter and Indian Chinese "-h" digrams, almost all UTF-8 characters, maxed out digrams/trigrams, some html, function keys, etc:
twiddler.cfg (2.2 KB)
I tested for how many characters are saved by digrams, trigrams, and "tion" in the total word list (2220 words with lots of typical repetition on common words, total 10010 characters). It looks like about 26 percent reduction. Not like a Stenotype machine, but I still think after a couple of years I might be faster one-handed than two! Yay!