It's perfectly possible to write short posts on LJ, and many people do. But on FB you can't write long ones, or even not-quite-short ones. Which is more flexible? Which can be more things to more people?

And LJ is a great aggregator. It was LJ's brilliance at aggregation that attracted me to it in the first place.

I have no idea what's going on among my friends on FB other than what B. tells me, and what she sends me are mostly Pat Wynne's cat pictures.