The specification seems solid enough, but direly lacking in key areas which seem to be commonly requested in portal development, I usually find myself longing to re-implement the 15 or so Portlets in another web framework - which I'm currently convinced would be both faster and more cost efficient.
I'm wondering what your impressions are about Portlets, and if anyone have some good or bad experience they would like to share about it.
EDIT: The question is related to Java Portlets (or JSR-168/286)