At work, in Lync (worst IM ever), email, and so forth, I just switched OSs and I'm getting alot of irritation from the spell checker.
The sheer amount of jargon that it thinks are misspellings and tries to fix is staggering. Dozens per day, at minimum.
I'm assuming all of those would require custom definition. I can't seem myself going through the hassle. And even if the job is done collectively, our department has less than 50 people in it (maybe 70 if you include the data center). It's not a big enough community for it to spread thin.
Steno seems like last century's solution to the problem, not this century's.