I learned something about the 140 character limit in the last few days, as I've experimented with a piece of software that may or may not see the light of day.
We all know that a communication environment with a character limit is a unique thing. I haven't sung its praises because it's enough-praised by others. As an experienced writer, I'd rather self-impose limits, I can decide what's enough. There are some useful ideas that can't be expressed in 140 that could be expressed in 180, 250, or 360. The problem with inbetween-sized ideas is that it's not worth the trouble to create a blog post for them, and Twitter doesn't work if you stream together a sequence of tweets.
Anyway, here's what I learned. I will self-impose a 140ish limit if I make the text display really big, so that a web page can hold one idea. It's the "ish-ness" that's important. It's a soft limit, up to the writer. For some ideas I need to go over. Not all, not even most. But when it's necessary, it's nice.